Hey guys, need help with a little problem that starting to develope on a 96 GLE. About a month ago I started to nothice that my idle RPM's are starting to drop. Stitting at a light with my foot on the brake and the transmission in any gear I am at the 500 RPM mark. Put the car in park and the RPMs go up to 700. With the lower RPMs the car idles a little rough. any ideas of what might be happening? This is a totally stock 96 with 70,000 mile on it. So that takes out any mod problems.

thanks
AJ

 

your cat might be backed up or yu may want to run some fuel injector cleaner.

 

that's normal, the engine should idle on an auto at around 700 without load, and drop to 5-600 under load. If you want it a little higher, just adjust the screw on your throttle body.