KIA-Sportage Running Problem - Help!
My brother-in-law has a '97 2.0L EFI 4-cyl A/T (4-spd) 2WD KIA Sportage w/ 98,000 miles and suddenly developed a running problem. He's the original owner, has done all the maintenance work by himself and has never had a problem before. He says... he was driving on a freeway at 65 mph for about an hour. All of sudden the engine/vehicle speed started to drop. The vehicle's maximum speed dropped to like 25 MPH max and the engine speed remained at 2000 RPM even at WOT. No smoking, no vibration, no leaking - nothing obvious found under the hood or car. So, he got off the freeway and barely drove home w/o getting rear ended. That happened more than a month ago and the car has been just sitting in his driveway since. Last weekend, I visited him and noticed: With the trans in neutral, the engine would rev up to the red line (5500 RPM) and the throttle response was exlnt. But as soon as, the trans was put into D and start to drive, the maximum engine rpm was limited to only about 2000. We removed all 4 plugs and they looked all OK, nice tan color. We hooked up a borrowed (neighbor's) OBD tool and it displayed EGR valve malfunctioning. Could a faulty EGR valve cause the above symptom? A dealer is asking $200+ for a new EGR valve, which seems way too much.
Any help/input/diagnostic hint would be appreciated.