Mechanics

WITH SERVICE ENGINE SOON LIGHT

2000 BMW 323

Engine Performance problem
2000 BMW 323 6 cyl Two Wheel Drive Automatic 185300 miles

I have a 2000 BMW 323i with the service engine soon light on. It has been on for about two weeks now. I scanned it and retreived the following codes: P1188, P1189, P1478, P0170, P0173. I replaced the thermostat yesterday because it was stuck open causing the engine to never warm up properly, then I cleared the codes. I thought this would correct the codes as they refer to the short term fuel trim, but it came back on today and when I scanned it I got P1188, P1189 which I looked up and they refer to the O2 sensors B1S1 and B2S2. I thought it was a pretty long shot that they are both bad at the same time. Any advice would be great. Thanks!
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E46bimmer
December 11, 2009.




At 185k, why not replace them?

Dr. Hagerty
Dec 12, 2009.
I find it hard to believe that both front sensors on bank 1 and 2 have gone out at the same time. Seems like it should be something common to both banks. I just hate to guess at the problem and not be sure that will fix it.
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Tiny
E46bimmer
Dec 12, 2009.
Replacement is called for at 100k, you are at 185k. Is that correct?

Dr. Hagerty
Dec 12, 2009.
Yes that is correct, but I just find it hard to believe that both of them went out at the same time. I was not aware that they replace them as preventive maintenance, why is that? I will try and scan it again tomorrow and look at the freeze frame data to see what that says.

Tiny
E46bimmer
Dec 17, 2009.
As Oxygen sensors age they often have a tendency to become biased towards the lean side. Freeze frame data indicates what voltage the sensor is producing, not it's calibration. You usually cannot perceive a lean condition sensor, but it will show up in reduced emissions, especially NOX. I hope this helps you out, it is always good to be able to make an informed decision.

Dr. Hagerty
Dec 19, 2009.

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