When you pulled the codes for the O2 sensors what exactly the code reads? let me know. What I am getting at is to pin point if its a control limit on the O2 sensor or it is O2 sensor itself going south!!
billb
I will get the actual wording from the booklet after lunch, but if I remember, it says, "Oxygen Sensor #1" and "Oxygen Sensor #2." I don't remember anything about limits.
Its Table K11, code 0c and 0d I think in the Peake book. You have a Peake book don't you?
I am at work now and you may have something like PRE and /or POST Cat O2 with number. In this case I'll check the connection in the plastic box 1st (unlikely though) the plastic connectors for the the pre ones sit on top of engine under the plastic cover where it say BMW on the engine.
When I get CONTROL LIMIT on a particular sensor you know it is overwhelmed trying so hard to compensate for another problem. i.e too lean vs. too rich type of a deal.
Billb This engine only has 2 O2 sensors, pre cat, down under the car.
I had thought about checking the continuity of the harness from the sensors to the 'brain' but wasn't sure where the brain is. I'll try to trace it this weekend.
Even then, I don't think my multimeter has long enough leads!
The 1994 530I has Two - OE Type Before Catalyst; I have seen them for about $88 each. However my 1997 528I has 4 of them; 2 precat. 2 post cats
regards
billb
Yes and the effect of unplugging the MAF causes miscalculations with the volumetric efficiency of the engine and the calculations programmed into the ECM. Someone with more expertise may be able to tell us more. but I trust you get the idea that eventually you will cause a MIScalculation and/or error and hence a check engine light fault pointing at your MAF.
Billb
Not that many will care, but after replacing 2 O2 sensors, and a $165 diagnostic from the dealer, it turns out that the problem was in the fuel delivery system.
Fuel pump and both fuel filters were changed out. Car runs fine now.
Imagine that? A faulty fuel pump will cause hesitation, but pull 02 codes??
All you 3.0 v-8's might need to remember that one!
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