Scan Codes P1189, 1188

[LTL SU]

I keep getting the following codes when my check engine light comes on: P1189 and P1188. I have changed the following parts: oil, oil filter, air filter (from stock to K&N), fuel filter, O2 Sensors pre cat, and spark plugs. The 323I has 98,000km. The car runs fine, no hesitation or rough idle. Every time I clear the codes, the check engine light comes on again but never at the same interval.

Anyone have any suggestions?

Thanks

[topless318]

Can you get ahold of another code scanner? Some times I use my onboard scan and then use my Peake scanner. Just to make sure.

[LTL SU]

I did and it gave the same codes. It was a snap-on tools scanner. any suggestions?

[Jeron]

So what do the codes mean. Don't make us look it up.

[LTL SU]

1188 - fuel control bank 1 sensor 1
1189 - fuel control bank 2 sensor 1

Where are these sensors?

[Jeron]

I did some searching. The code is from the precat O2 sensors but not necessarily because the sensor is bad. Most likely it is a problem in fuel delivery.

You've already replaced the fuel filter. Other repairs I've seen were MAF sensor and Cyclone Separator or general vacuum problem.

http://tech.bentleypublishers.com/thread.jspa?forumID=69&threadID=2917&messageID=9430#9430

Blindly replacing the cyclone separator would not be a bad idea, they tend to fail at 70-100k. I would test the MAF and check for vac leaks. You can probably find more info on the web. I only spent about 10 minutes searching.

[Acegolf]

Originally posted by LTL SU
I keep getting the following codes when my check engine light comes on: P1189 and P1188. I have changed the following parts: oil, oil filter, air filter (from stock to K&N), fuel filter, O2 Sensors pre cat, and spark plugs. The 323I has 98,000km. The car runs fine, no hesitation or rough idle. Every time I clear the codes, the check engine light comes on again but never at the same interval.

Anyone have any suggestions?

Thanks

I had the same codes on my 96 328i. Corrected them by swapping the O2 connections on top of the engine. Seems as if i connected them wrong when i changed out the old O2 sensors.

[LTL SU]

thanks for all you input and help. It ended up being the crankcase breather valve and hose.

Joe

[Jeron]

Goes to show what we know. LOL

Wait..

The crank case breather valve IS the cyclone separator.

[paxcam]

I wanted to add a footnote to this thread as I spent almost 6 months fighting P1188 and P1189 codes.

Not until I stumbled upon Acegolf's note about swapping the O2 leads did I find a fix. Co-incidentally, we both have 1996 328i's.

I just want to share this knowledge with the group as I spent hundreds of dollars replacing parts that probably needed replacing after 195k miles, but in the end, the simplest answer was the one thing that made the difference.