My wife's 91 300TE w/ 130k miles: the "check engine" light came on when she was on the freeway yesterday. I looked at it after she got home and when I drove it the light was still on. The car drives fine: same amount of power, etc. The owner's manual says to look at the O2 sensor and for Calif. cars maybe the FI system as well. It also mentioned the keypad by the battery to get the fault codes stored in the computer. This is a Calif car (if it is any different from the "federal cars") I should probably get the fault codes. How can I do that? I watch a mechanic did it once but I can't remember...

I will check the achives and see if the collective wisdom of the list can give me some answers.

1: Can we still drive the car? My mechanic is on vacation till next week.
2: Is it likely that I need a O2 sensor? Where to get one? Can I do it myself?

Happy new year! and TIA for any comments.

Sincerely,

Paul Lee

On the california car there is a LED blink light on the diagnostic connector. Turn key on, push button for 3 seconds and the first code can be read. The number of blinks is for 1 (each) code. To erase that code after counting, press the same button & count slowly to 8, and that has to happen with-in 10 seconds of the last blink. Then see if there are any other codes by following the same sequence. When the light blinks only once after the 3(three) sec. push; there are no more codes! There is an emission problem w/car, most likely no problem with driving!!

I check the LED and it blinked 16 times. I did it 3 times and it only showed the 16 blinks. From checking the achives I think that means the EGR. I looked at the EGR valve and the hosed from it and everything seems tight. I should probably warm the car up and see if the valve is working with the throttle. I don't have a book about the MBZ EGR valve but my VOLVO manual list a trouble shooting section on EGR valves. The EGR systems on the two cars look very similar. ANy other suggestions. I also reset the "Check Engine" light.

Thanks

Paul