1992 300CE M104 Check Engine Light (code 11)
 

Well, I scoured this forum for a possible solution to my newest code, but to no avail.

I was able to read and clear the code. The guide that I have states that code 11 is a problem with the air injection system and likely an open or short circuit.

Any thoughts as to where one should begin and what might be most probable? If this topic has been discussed before, please direct me to that thread.

Any help is appreciated.

Thanks!

Michael B.

Broken vacuum line from switch-over valve to diverter valve is most common issue.

Thank you Mr. Moderator! I'll begin there tonight and report my findings.

Vacuum is present at the switchover and diverter valves. However, the Check Engine Light (CEL) comes on about 24 hours after the code is pulled and reset. I have two 300CE's of the same year and they sound the same on start up (air pump noise), but for some reason, the one in question keeps setting code (11).

I don't really want to do this, but one thought I have is to maybe swap switchover valves (from car to car) to see if the code appears on the other one.

Is there something else I should check?

Thanks for the help!

1992 300CE M104 Check Engine Light (code 11)
 

Anyone got any ideas? Where to look or how to test? Thanks!

Have you tried swapping the valves from car to car.....

Nope. However, she's now for sale and the new owner picks it up Wednesday.