OBD1 e36 check engine light...turns on and off from 2000 to 3000 rpm.

**dunebuggyjay** · 11-24-2015, 06:27 PM

Hi Guys,

Why does my check engine light light up sometimes when on the highway? Between 2000 and 3000 rpm, it will sometimes come on....then shut right off it I give it a bit more gas, or less gas.

I always get a code for O2 out of range. 1222.

O2 sensor is new.

But why doesnt it stay lit? Wondering if i have any other issues.

Engine is an s52 thats been converted to obd1. (its in a 88 E30)

I also get a hell of a misfire when going full throttle. Sounds like I hit a rev limiter.

Ive tried 2 differnt sets of coils and I get the same issue. My wideband meter shows it way rich when this happens. (9 afr) so wondering if my dme or injectors are bad. I swapped in another dme today at work during lunch, and will drive home in a few minutes to see if it is my issue.

Any advice?

Ive got a new crank sensor, new cam sensor, new coolant sensor for the dme, new plugs, fuel pressure is good, new fuel pump.

Not sure what else it could be. I just ordered a TPS to try out, and another o2 sensor in case for some reason mine is faulty. (its a new bosch unit i put in like 2 months ago.)

Car has never run correctly. I have never been more than half throttle in it without it running like crap.

Part throttle and on the highway cruising seems good. It idles pretty good too...except it seems once I get off the highway, it is a bit lumpy for about 20 seconds...then it idles fine.

Thanks for listening.

I open to suggestions.

Thanks
Jay

**E36Phoenix** · 11-25-2015, 01:05 AM

Sounds like an air issue. Checked for vacuum leaks? My car was doing that when i had a vacuum leak. Also, have you checked the exhaust for blockage?

**dunebuggyjay** · 11-25-2015, 09:47 AM

I did check for vacuum leaks with carb cleaner. I couldn't find anything.

When i installed the engine 3 months ago i did replace every vacuum line, and all the seals on the manifold and throttle body.

I plan on making myself a smoke tester to try that out. But im pretty sure i dont have a vacuum leak. My crankcase vent is separate also (I run a catch can vented to atmosphere. With the ccv stuff all blocked off. )

Exhaust is all new when i did the engine install a few month ago. Cat is a new magnaflow unit. I am running a AA Tuning catback though.

I have noticed a slight tick in the exhaust this morning. I never heard it till today. It looks like it may be between the header and the engine. Wonder if that could be my issue??

If its screwing with the O2 sensors readings..by making the dme dump more fuel in.

I just ordered up some new gaskets for it.

Jay