Now even though I did not notice any driveability problems, I had to be concerned, something may get worse, and I can not pass NJ Auto inspection with that indicator lite.

So, I took it to the dealer and about $270 later I had a new Oxygen Sensor ($100 parts + $160 labor + tax) and the SES was no longer lite. I think I also got a quick overall inspection, which is worth something given they have all the GM notices and warnings. They found nothing else needing attention - thankfully.

Well, the above makes me wonder about buying a Code Reader, I could have changed the O2 Sensor myself and saved the labor charge, and I think I could have purchased the sensor from NAPA for less than the dealer parts charge.

I see in Harbor Freight a OBD II Code Reader With CAN for $40. So, if it could have put me onto the O2 sensor it would have paid for itself 4 times over with the one repair just completed.

Now I know HF sells "junk" or at least "you get what you pay for" so my question is more the subject of this post than how good is the HF tool.

Is a Code Reader something today that every shade tree mechanic (DYI'er) should or must have?

There some caveats, however. Code readers available over the counter may not have all the functions that are in professional units, and one of those omitted functions may be the ability to reset the maintence light for the oxygen sensor. As I understand it, it is illegal to reset the maintence required light for the oxygen sensor without changing the sensor. The dealers and repair shops that I know will not reset the Oxygen Sensor code unless they change the sensor. I have one repair shop that will accept a sensor that you purchase, but they must do the install.

If your main reason for buying a code reader is for resetting the maintence codes, check to see if it has that capability before your purchase.

I have changed oxygen sensors and you are correct in that it is not difficult in most cases. It is best, though, if you have a special socket with a relief for the electrical leads.

It sounds like the O2 sensor is a bad actor...or because it has a strong influence on emissions the on-board computers used these days keep a "close eye" on that effect. It may be that on older cars/trucks I've had I drove them for years with a faulty O2 sensor and the inspection station never detected omission problems...but I think the one time I changed one it may have been because of a failed inspection result..too long ago for me to remember.

I had assumed the SES would automatically "reset" when the error was fixed, e.g., in this case the O2 sensor replaced.

When the engine controller sees an out-of-bound voltage from the oxygen sensor, it ignores it, sets a trouble code, and uses default settings which may be on the rich side. Thus the engine will continue to run, but may not pass an emission test (at the tail pipe), and your fuel mileage may be reduced. It will not pass the code reading part of an emissions check.

I didn't even look to see if there was some scheduled maintenance needed on the O2 sensor. The only interaction on maintenance I've had is changing the oil/filter and fluid levels, and they haven't needed any adds. The low mileage usage means I have only changed the oil once a year, the "oil life" computation never comes on, but I still have to reset that, and it is the only user reset supplied with the interface.

The cost of the dealer doing the work isn't a big "waste", but I had in the recent past used a local gas station garage for work on my older vehicles. He'd likely have done the work for a lot less, and I assume he has the code reader expertise to reset. Still, the 4 year point is a good point to give the dealer's shop a chance to look for troubles based on the full GM experience...besides, and sadly, we may not have a GM shop in the future. These are tough economic times.

How much do you really want to know about the humble little oxygen sensor? Got a day or two to sit in a formal class?

The MIL will come on if the vehicles on-board diagnostics detect a condition that indicates that the vehicle "might" be polluting the air in excess of 1.5times the FTP testing for that vehicle platform. It does not have a scheduled maintenance for the O2 sensors at any mileage or vehicle age. The PCM's programming performs both passive and active testing for each and every sensor, as well as each and every component that the PCM controls. This means the O2 sensors, as well as every other sensor, and the sensors circuit. Just because you get a P0101, Mass Air Flow sensor performance, it does not mean you have a bad Mass Air Flow sensor, and the O2 sensors are not an exception to this.

In the event a single sensor fails, or appears to have failed, the vehicle actually does not rely on base programming any more. First it relies on the companion sensor for a "V" engine, and it also relies on the downstream sensor(s).

Otherwise known as a "LAMBDA" sensor, the one thing an oxygen sensor does NOT sense is in fact oxygen. A/F sensors as found on many smaller engines (growing numbers since 2002), and just about all across the board with 2006 and newer vehicles that the ability of the sensor to report the actual air/fuel ratio to ever higher levels. Previous to that, an oxygen sensor simply switched between a high VS low voltage output depending on whether the air fuel ratio was slightly richer or leaner than stoichiometric. "Stoich" is generally referred to be 14.67 to 1, but when fully understood, that is an average, and not a single exact number.

Top independent shops are not necessarily cheaper than the dealer, in fact it can be shown there is every reason to expect that they actually could be a higher price, and yet still a better value!

Aftermarket code pullers are the one thing that I have no experience with. As a full time tech, I understand that the code by itself is little more than the first step of the diagnostics. Pulling the code, and then throwing a part is not doing diagnostics, and repairs of a vehicle. Sure you can get lucky and the code will in fact identify a failed component. Try and work that way in a shop, and you'll quickly earn the reputation for not knowing what you are doing because of how often you would fail to repair a customers car. However if you did guess correct, and you replaced the part, you would then after driving the vehicle a few days when the PCM has had a chance to actively test the sensor and saw it pass the on-board tests two times consecutively, the lamp would in fact go out on the next restart and the code would then be stored to history. Then after another forty to fifty restarts if the code did not reset the code would be erased completely. (in most systems, only retrievable then on certain ones and the tech has to know how to go looking)

Thanks, good to see you are still on this forum and taking the time to provide welcome and useful tutorials. I don't post here often, but have gotten similarly good advice from you in the past.

Interesting on the independent (which you are) being possibly better than the dealer. I can see that could be the case for a experienced independent (such as you) who also keeps up-to-date. I think some are glorified shade tree mechanics, who were fine for cars back in the 60s. Then too, I suspect the dealer may have some "green" trainees who don't have a keen eye/ear or a vested interest in the shop surviving, well not as much as an owner.

I'll save a copy of your helpful note, for future reference.
I'm a old guy and figure with my poor sight, hearing, and mind it is best to have most repairs done, rather than DYI, but I still give it a shot once in a while...I installed my own trailer receiver hitch on the subject truck when it was new, and I haven't lost a trailer yet, but then I haven't driven many miles yet either.

I have the 2.8 4 cylinder with manual everything, the low-end truck. Consumers doesn't give the Chevy Colorado good grades on reliability... what's the experience on this forum? What should I look out for, other than the bad valves for which I have an extended warranty..to 7 years and I figured it could have been the cause of the SES light, but the dealer's shop said no, it was the O2 sensor and I can say the SES is no longer lite.

Thanks again, and keep up the good work for your customers who can't afford a new car because of the poor economy.

People used to spend a small fortune in gas, wear & tear, lost time and lost work traveling to the discount auto parts stores for free code readings, paying garages for code readings and paying garages big bucks for relatively simple repairs.

Many of our customers with code readers use code readers, automotive manuals, mechanic's software and the internet to troubleshoot dozens of vehicles belonging to family, friends, neighbors, co-workers etc.

The flat economy has effectively forced many employment/income/savings/credit challenged people to become self sufficient electrical/emissions troubleshooters and/or forced them to use the services of unemployed/under-employed mechanics that work from home, or on-site.

I just fixed an intermittent electrical issue for customer that spent a small fortune with 3 different garages that failed to fix the problem.

Having a little knowledge also helps prevent customers from being taken advantage of by dealerships, independents, tire/brake/inspection outfits etc.

Many service outfits are getting pretty desperate for work judging by the amount of places advertising 99 cent New York State Inspections, free inspections and heavily discounted services.

I have been thinking along the lines you describe. In fact, when I turned my 2005 Colorado into the deal shop I listed two problems: Service Engine (must be fixed to pass NJ Inspection - I think NJ does not use the code reader, just looks at the dash Icn) and the Security fault. My truck is a basic model, manual windows and locks, no electronic security. The dealer shop was successful in getting the SES Icon off, and in applying two "silent" recalls (not happy I didn't get a notice), but the Security fault did not result in any action... I'm concerned it is a computer problem, expensive to repair. The problem may be that the Security fault isn't on all the time, so if I had a reader I could look when it is on. Still I think the problem would not be uncovered as the vehicle isn't equipped with anything that can be fixed.

If there is one thing that annoys me more than anything else in this trade, it's the never ending line of people who tell the customers want they want to hear whether its accurate or not. Reminds me of the service manager that told one old lady that the fog that she kept finding on the inside of her car windows was a small coolant leak and we simply had to tighten a hose clamp, instead of telling her that as the vinyl interior cures it will give off chemicals that can fog the glass and it will go away completely by the end of the summer all by itself. I think I saw that car in to get the windows cleaned every week all summer long. What the service manager did was tell her what she wanted to hear, that something got fixed.

You wrote "I just fixed an intermittent electrical issue for customer that spent a small fortune with 3 different garages that failed to fix the problem. "

It takes four things to be able to fix a car. The right person, the right tools, sufficient training, and a broken car. Intermittent by nature are a car that isn't broken all of the time. If it happens to not be broken at the time that any of the other three shops saw the car, then they had no chance. Now keeping in mind what I started off with, people in this trade wanting to tell the customers what they want to hear, instead of the way it really is, you can go right ahead and fault the shops as you did, and play the hero card here. The facts are the forces at work inside of this industry that you allude to are going to hurt the consumer until we all learn how to be professional.

Quote" The flat economy has effectively forced many employment/income/savings/credit challenged people to become self sufficient electrical/emissions troubleshooters and/or forced them to use the services of unemployed/under-employed mechanics that work from home, or on-site"

Side work is stealing, pure and simple. Someone doing side work has no insurance, which a shop has to pay in order to protect the customer as well as themselves. They don't pay taxes which short changes everyone else that does. They operate in the street, or in a garage not zoned for the business, the list goes on and on. It's the classic apples to oranges kind of a comparison. You cannot compare what happens in someones back yard to what a real shop does today.

Quote "Having a little knowledge also helps prevent customers from being taken advantage of by dealerships, independents, tire/brake/inspection outfits etc"

Now where does one get this knowledge? In some back alley? Here on the Internet? You can find videos of people unlocking a door on the Internet with a tennis ball that has a hole cut in it. Its fake, but people want to believe it. Your response is IMO another tennis ball trick that unfortunately I don't have all day to debunk. Plus I have the disadvantage of having to tell it like it really is, not the sugar coated version that people want to hear as you did. Yes it costs money, and sometimes you might consider it "big bucks" for something that may seem relatively easy. Did you see Jerry's response just now?

Quote " and the Security fault. My truck is a basic model, manual windows and locks, no electronic security. The dealer shop was successful in getting the SES Icon off, and in applying two "silent" recalls (not happy I didn't get a notice), but the Security fault did not result in any action... I'm concerned it is a computer problem, expensive to repair. The problem may be that the Security fault isn't on all the time, so if I had a reader I could look when it is on.

The reality of that paragraph is first that Jerry contradicts himself in saying that the vehicle has a Security issue, but at one point says that its a base model with no electronic security. Not blaming him of anything here, but in a way that's a classic perception, and not an uncommon description that a customer might give to a shop. The security issue is likely real, plus it's intermittent. Tell me Mark are you trained and equipped to service that system? If so what scan tool are you using? (brand and software updated to 20XX model year)??

Sadly this is going to end up rhetorical, because I have to give the answer to make my point.

Real techs today, understand that the ONLY tool to service that system correctly is the GM tech II, and the shop has to have a subscription to SPS. What tool would you use if Jerry would happen to own a Ford with a similar reported problem? How about a Toyota; or a Mazda; a Honda, an Acura, a Lexus, a Nissan, an Infinity, a VW, a BMW, Mercedes, Kia, Hyundai? Or any one of the other manufacturers currently available in the US market? The reality is techs and shops need vehicle specific training, and specific O.E. tooling for each one of the manufacturers or else they are working with a handicap, and potentially will find themselves unable to actually complete a given repair without sending the car back to the dealer, or having a mobile diagnostic technician come to their shop, or in fact they could come to a shop like mine for about 90% of the most common vehicles on the road.

I ask you Mark are you genuinely equipped and trained to service the security system on Jerrys Truck? Would you be for all of the other manufactures that the readers here are likely to own?

By taking on that expense, uncommon in the industry, it impacts what a shop like mine has to charge for even the things that are indeed easy. You attempted to make that look as if it is dishonest with your response and I take extreme exception to that.

Dealerships, by their franchise agreement, have to be equipped for, and employ techs who are capable and trained to service things like Jerry's Security system. Only shops and techs who "get it" in the aftermarket step up to the plate and make the required investment in the tools, training and equipment required to do the complete job. Customers who understand this, realize that there are many ways to undercut the real professionals, but understand doing so causes either the professionals to charge even more for what they do, or else they have to dial back the services for which they are going to be able to perform for the customers. Or worse yet, simply shut down and no-longer be a viable option for the public.

Think that's an exaggeration? Look at how many dealers are being forcibly shut down. If your above average, your still not trained and equipped to fill the void caused by a dealer that closes. I can't do that simply because of the volume of work that could be displaced. (There are only so many hours in a day). Back yard Bob isn't going to do it, because he wont go to any updated schools, and he darn sure won't buy the tools.

Auto repair isn't cheap, it's actually under priced for what it really takes to do it correctly, and armed with the knowledge that is based in reality, a customer has a chance to find a real shop that will repair their car. That's my goal here Mark, exactly what was yours?

I do understand, without any confusion, that my basic truck does not have any of the security features that the truck readout indicated was malfunctioning. That's part of the reason I suspect the computer, i.e., there is only one computer and it has options that may or may not be equipped, in my case the wireless key lock is not equipped (in fact my truck is so basic it has a key access only on the driver's side, none on the passenger side). That is also one of the reasons I was dissatisfied with the non-response by the service tech (who the dealer advertises are fully trained)to my complaint about the security fault display.

I was about ready to live with it as it should not (I guess) disqualify my vehicle at NJ inspection. But, related or not, the engine starter started to malfunction, not cranking the engine when the key is turned, but when the key is released to the "on" the starter cranks and the engine starts. I assume the security system has some function besides blowing the horn and flashing the lights (which doesn't happen), perhaps it also opens the starter circuit.

At what appears to be about $150 an hour at the dealer's shop I'm not in any hurry to take the truck back, as long as it continues to start.

I was about ready to live with it as it should not (I guess) disqualify my vehicle at NJ inspection. But, related or not, the engine starter started to malfunction, not cranking the engine when the key is turned, but when the key is released to the "on" the starter cranks and the engine starts. I assume the security system has some function besides blowing the horn and flashing the lights (which doesn't happen), perhaps it also opens the starter circuit.

Jerry, I think you are confusing the security system for a burgular alarm system. The security system is just an ignition interlock system or VATS system. No horn,head light,sirens or any other noise. The system just looks to see if the right key is being used. If not it wont't let the car start. If you still have your owners manual look at it and it should discribe the security light function.

Good Luck
With It

Bob

That said, I have not had any problems with the false Security warning in the past three or four uses of the truck, including this morning in which I twice locked (manual setting from the inside) and unlocked, using a physical metal key. Maybe this has all passed :)

I don't have a goal, I'm just describing the reality of the automotive diagnostic, service and repair business, not what's right or wrong.

Will it override the controls and command the right rear window to raise and lower for testing on a 1997 Cadillac Fleetwood? Of course it won't but that's just one of the thousands of things a tech needs a scan tool to be able to do.

Will it support EVERY module on that same Cadillac mentioned previously, ABS, SRS, MMM, Radio, PCM, BCM, Drivers Door, Passengers Door, Rear Drivers Door, Rear Passengers Door, HVAC, Power seat. Will it support every function each of those modules is capable of, such as the display of serial data, the bi-directional control of every relay, solenoid, motor they control. Is it capable of retraining the theft deterrent system, key fobs, pass through and or stand alone programming?

Seriously, not a single aftermarket professional level scan tool can actually complete that list on this one twelve year old car, not Snap-On, not OTC, EASE, Auto Enginenuity, none of them. That's why to service the car on par with a dealer tech the shop must have the GM tech II, for GM vehicles. The shop also must have the Ford IDS for Ford and Mazda vehicles. The Honda Terradyne, Toyota Vetronix Mastertech, and the Techstream, Chrysler DRBIII, and Starscan/Starmobile (already being replaced by WiTech), VagCom for VW/Audi, and the list goes on and on.

Generic OBDII standards are usefull only to the same level that a matchbook and screwdriver are to attempt to reset the gap of a set of points was. If the car then started one often claimed they could do everything that a pro could. Otherwise......

I raise a complaint with GM that while the truck is 4 years old, it had just over 10,000 miles on it, less than one year's use and for the ignition switch to fail with that little usage it had to be defective - they agreed in part, and I took the offer to split the bill 50/50.

Good Luck With It

Bob

No you don't want to meet me (or anyone else in this trade) if your out on vacation, but the reality is, you also don't want to meet a dentist in an emergency situation, a doctor, a police officer, a fireman, or any other person who's chosen career is one that is aimed at solving a problem you probably didn't expect to be facing on that day. But never the less, we get up and go to work and are there for the people who suddenly need us. Yes, we even get up in the middle of the night to go out and help someone we never met before, who just might exactly as you did on your last response for us taking the trouble to do so.

All your attempts to insult me, are extensions of the oppression that gets thrown at people who work in many of the trades. I don't have to quote your ignorance, everyone can scroll up and read what you wrote. Yes, people can just "get rid" of a car if it doesn't perform the way they want it to, or if they simply decide they don't like the color anymore. People that know better understand our trade allows them to keep the car operating correctly for fifteen to twenty years, and they reduce their transportation costs to 1/4th of those that follow your get rid of it advice.

Plus it takes more to be a technician and do the work that we do today than that $100 toy. You didn't know what you were talking about when you wrote that first post, and you haven't learned anything since.

No, I haven't purchased a scanner. The idea came to me when I paid the dealer to turn off the "engine light" and change the O2 sensor (I see my new Suzuki SX4 has two, 02 sensors, now I really need a reader :) ) Changing a sensor isn't a big deal, even for a "shade tree guy", I've done it before. I do not intend to become competition for the professional mechanics, dealer or independent (I've frequented both - yes I'm an old guy, so I've had a lot of time for experience) I just like to fix simple things myself, and if a new tool that cost about the same as one of the simple repairs does have an appeal to me.

I take all the great input as helpful... and I may buy one when an engine light comes on again. This 2005 Chevy truck is my first experience with that light coming on.

They don't need the functions of his professional scan tools, since they go to the dealerships for most specialized service. The independent garages they once used charge as much, or more than the dealers that are more experienced and better equipped to handle vehicle specific service and repairs.

We see something similar in the heating industry with customers buying their own combustion testing equipment since service, emergency service, troubleshooting and repairs are very expensive and/or service outfits don't have the proper test equipment, don't use it, or have employees, trainees and helpers don't know how to use test equipment properly.

Over the years I've done many jobs, some automobile mechanical, that when done I felt: Now I know it is done right, other times I concluded: Should have hired it done, and will next time... that has been the case for most exhaust and brake work, haven't done any of that for 20+ years, but I could if I had too.

http://automotivetestsolutions.com/about.htm

BTW Mark. The most experienced technicians in any vehicle line are not found only at the dealers. In fact because of specialization the most widely experienced technicians are definitely not in the dealerships anymore because of both the cost to train them, as well as because of the salary demands they would in turn be able to make. Anyone who has not been using the techniques like the ones outlined from Bernies website, is years behind in the training and experience of the top independents. When the local dealerships call me in to assist them with diagnostics (yes, they call me, NOT the other way around) and then see me do something like use pressure transducers (Bernies system) to verify cam timing without tearing down the engine, they understand why I am able to efficiently figure something out that was kicking their behinds. Oh, BTW Bernies system will set you back about 100 times that toy code puller, and again, the tech still needs the O.E. scan tool for the vehicle he/she is working on to go along with that.

Besides the fear of auto service garages not doing a job right, many customers are also paranoid that the auto service garages will charge them for parts not replaced, services not performed, sell them parts and services not needed and/or pad their bills with extras, additional labor, ultra high parts mark-up etc.

Time, distance, towing fees, hassles of dropping vehicles off, picking vehicles up, renting vehicles, borrowing vehicles, missed work, lost money and lost time are also reasons why people choose to do their own work, or seek the help of friends, relatives, neighbors, shade-tree mechanics or mechanics doing side-work.

Money is a big driver of DIY repairs, especially in tight economy. Many people are unemployed, under-employed, money and credit are very tight, plus they have more free time to perform their own service and repairs. In addition, when people perform their own repairs, they end up acquiring tools, equipment, knowledge and skills that they can use on future jobs.

http://ths.gardenweb.com/forums/load/cars/msg1022082722450.html

I'm sure you're wealth of experience will be enough to give him/her all of the correct assistance that they need. Maybe you will even drive to where ever they live and try to use your code puller to help them. Or else of course you could just wash your hands of all of this and leave them to spend a couple thousand dollars at the dealer.

Well whatever it takes right? There is no way some independent technician has the correct tools and training anyway to efficiently deal with that VW so they are easily going to be better off with whatever advice some DIY'er can give them, AND then they can spend a couple thousand at the dealer.

Now imagine for a moment, that an independent would have known exactly how to deal with that VW problem, only to have them not be available because of your actions. You can have that example here in this forum right now because it parrallells the reality out in the real world. Yes, I know exactly how to approach the VW issue, and have all of the right tools and well, training? I'm an instructor for VW/Audi aftermarket Con-Ed, so yea as the instructor I certaintly have the training. But if the other guys can't be profitable, how can they afford to go to even more schools?

BTW yes, at the "silver bullet" level I likely do know and could probably tell them exactly what is wrong with that VW. But sorry I need to go cut some firewood. The furnace at the house is low on oil, nobodys spending money fixing their cars so I can't go buy more. I'm going offline and will be unavailable, YOU ARE ALL THEY HAVE!

You wanted it you got it. BYE!!

TDDWHHPBTBWWITGCFTDDM. Acronym sentence for the likely cause of the VW issue.