99 M3 p0170 p1188 p1189 check engine codes

[Shafeeq]

I have owned my 2 dr 1999 e36 M3 now for over two years, without any problems. Recently, however, the "check engine" light came on. After reading the codes with the OBDII tester I got from Autozone, the car read the followinge errors:

P0170 - Fuel Trim Malfunction (Bank 1)
P1188 - Fuel/Air metering (Bank 1, Sensor 1)
P1189 - Fuel/Air metering (Bank 2, Sensor 1)

I checked the gasoline cap, changed the fuel filter, and reset the light. After a few drive cycles, the light returned and with the same p1188 and p1189 codes. Now the guy at Autozone said that its most likely the 02 sensors, but is it possible for more than one of them to go out at a time? Also, what is the differnce between the "banks" and "sensors?"

I have not seen any decrease in performance or gas milage. Plus, I don't want to have to replace all 4 sensors at $100-150 a pop unless its really necessary. What are the other possibilities?

I'd appreciate any info you can give me on my problem.

Thanks,
Shafeeq

[dboyles]

You shouldn't have to replace the two post-cat oxygen sensors. Bank 1 refers to the exhaust manifold for cylinders 1-3, and Bank 2 for the manifold for cylinders 4-6. Although I'm not sure what "Sensor 1" is, since there's only one sensor per manifold. Perhaps someone else can shed some light on it. I haven't tackled this job yet on my '99, which brings me to my question: how many miles have you got on your car?

[Shafeeq]

The car has about 80,000 right now. From what I've read, they should be replaced at 100,000 mi, so I'm still a little bit early.

-Shafeeq