99 Z3M - Unusual Check engine light

I purchased my Z3M Coupe in February of this year with 106K on it. Until Friday it has run without a hitch. Driving home from work I was greeted with a CEL. It doesnt run any different. The gas cap is tight, no wires or hoses loose, and the air filter was changed 2K miles ago with the oil, oil filter, and fuel filter. I suspect it may be a 02 sensor as I have been running some Lubro Molly injector and valve cleaner through it. It currently has 118K. Any other Ideas?

I purchased a reset/code reader from Bavauto and it is on its way. Any thoughts would be appreciated.

Too many potential causes to speculate, best to just read the codes and act upon the information given.

Right on... Should be here in a day or so. Didnt know if there were any maintenance intervals that would cause CEL to light. Love the car it has really captured my interest and given me an excuse to focus on something other than work. Thanks

Okay codes E4 and Cb Ox sensor codes.

This is what I suspected as I have been running some of the Lubro Molly injector and valve cleaner through it. I cleared the codes and it ran rough for a few minutes. Took it for a drive and let it warm up good. It seems to run fine now, and the CEL has not come back on.

Any recommendations?

Originally Posted by barearrow

Okay codes E4 and Cb Ox sensor codes.

This is what I suspected as I have been running some of the Lubro Molly injector and valve cleaner through it. I cleared the codes and it ran rough for a few minutes. Took it for a drive and let it warm up good. It seems to run fine now, and the CEL has not come back on.

Any recommendations?

Sounds like the Lubro Molley should take a hike. ?