1989 300se check engine light
 

I own a 1989 300se with 60,000 miles which drives fine, but recently the "check engine" light is coming on intermittently. Any ideas of what to look for without going to the shop? I do not have a diagnostic tool for the codes.
Thanks.

O2 sensor is usually what causes the check engine light, but you really need to read the codes and/or check the mixture and duty cycle for the feedback loop to be sure.

Peter

Do your back-up lights work...climate control? The CEL is on the same fuse. When the fuse fails the CEL is activated. At least on a federal '90.

Codes are real time only, unless you are in california. This is why you need to provide you LOCATION.

CA cars are different.

I believe that the CEL is supposed to come on at 60,000 miles, and again at 120,000 miles. This is the O2 sensor replacement interval.

Well, you can see if your o2 sensor is working pretty easily, in that case.

Don't see to many 60k mile 126 cars anymore. :)

Curious...how does the odo know to trip that light?

Your diagnostic tool is a multimeter, and this site, of course. :cool:

I can't remember. A lot of similar era volkswagens have the same thing. Like a secondary odemeter. Honestly, I have completely blanked out. I may have dreamed this up.