How long is the exhaust ducting from the wall to the flapper outside? The entire path of it must be checked and cleaned if necessary ... not just the flex-duct between the dryer and wall, and the flapper at the end outside.

Also make sure the flex-duct is short and straight as possible, not kinked, or sharply obstructed.

To confirm whether the dryer is heating to proper temperature:
1) Disconnect the duct from the back of it.
2) Set it on the TIMED cycle (set at least 30 mins) and HIGH temperature.
3) Let it run for a few mins to get fully heated.
4) Check the exhaust air temp with an instant-read kitchen thermometer. It'll vary between a maximum and minimum reading as the burner cycles on/off to maintain a target operating heat. Should run between about 145F to 155F at max and drop to maybe 125F to 120F minimum.

This is a gas unit. If there is a problem, could be a flaky gas valve or a bad flame sensor, among other things.

Ive had great service from all my Maytag gas dryers. I think the only things I have ever had fail other than maybe a drum bearing is the gas valve solenoid coils. They tend to get weak over the years and usually will work fine when the cycle starts but get weak and fail before the load is done.

You are in good hands with Dadoes for diagnostics. Dont fear working on it yourself, these machines are easy to work on.

dadoes & fordtech

Thank you both for such quick responses. I appreciate it so very much!

I have cleaned out the entire path and even after disconnecting that silver coil (vacuumed inside the coil also) flex duct I looked inside the hole in the back of the dryer with a flashlight to make sure there wasn't any lint at all.
I ended up vacuuming every square inch of the inside after taking off the front panel.
That's why I ended up feeling so overwhelmed.....each site told me the lint in any of areas could be causing the problem and once the lint was removed the problem should be solved.....it isn't. :(

The hole leading outdoors from the dryer is straight. I have less than 2 feet of coil. I wouldn't have that much but when we got the dryer I wanted some space between dryer and back wall for ventilation.

I will go get the kitchen thermometer and test now.
I am sure I will be back. :)
I initially bought this, my first Maytag, 6 years ago because I needed large and the fantastic reviews.
I am hoping if I need a part it won't be too expensive (gas valve solenoid, flaky gas valve or a bad flame sensor). I really love my dryer.

Again, thank you both so very much!