EMS Error code P1087
 

Need a little help if anyone can offer it. I have an error code coming up on my '01 330ci with 105K on the odometer. I believe it deals with the sensors on the exhaust manifold. I have replaced both sensors on the exhaust manifold as I thought this was the issue. The SES light comes on after about 100 miles or so of driving. The code P1087 is "O2 Sensor Circuit Slow Response in Lean Control Range (Bank 1 Sensor 1)" and I've also had a similar code for Bank 1/sensor 2 as well (P1089). I've cleaned the MAF sensor as I read this may have a barring on it and continue to have this issue. Is there something I am missing or any suggestions?

Appreciate the help...

Clear them and see what comes back. I like obd-codes, allexperts and forums at Bentley Publishing to look up posts about OBD codes.

Codes still come up after 100 miles of driving (I drive about 150 per day for work). "System too lean, bank 1" and "System too lean, bank 2", and the actual codes that come up on my scanner are P0171 and P0174. This things beginning to tick me off.

Any other suggestions???

I'd look up the codes on the websites I mentioned above.

To me it means you have a intake leak or fuel delivery problem because I doubt both O2's went bad at the same time.

I'd check the intake tube all they way to the intake for cracks. Make sure to bend it a bit and take your time. Check for loose or cracked hoses at the intake.

Check MAF sensor and the fuel pressure and flow.

Hopefully your search for the codes will reveal something.

Thanks. I did clean the MAF with electronics cleaner and while I was at it replaced the air filter. I'll check for leaks/cracks, replace the fuel filter and check over the fuel delivery system. Always something...isn't it.

Thanks again...

OK, it's back. Same code, P0174. I've replaced, as mentioned above, two sensors, lower intake boot and the fuel filter (what a joy that was!!). No cracks or leaks on the intake side that I can see or hear. Any suggestions? I also had another code come up that indicated a misfire in cylinder #6, so I'm going to replace the coil as I just replaced the plugs a few months ago, but i doubt that had anything to do with it.

With 125000 miles on it, I guess a few things can go wrong sometimes...