My roomates 1995 Buick Park Ave (with the supercharged 3800) has been triggering the Check Engine Light occasionally, so I finally got around to checking it out for him because he doesn't know anything about cars.
Two trouble codes are set in the history log... one is for the O2 Sensor reading too low, and the other is for an indicated lean condition.
The readout from the O2 does indeed show it reading very low, but the reading does bounce around like I would expect and does get up to higher readings under certain operating conditions. The O2 sensor was replaced only a few months ago, and gas mileage is about where it should be.
The scantool also shows a percentage of indicated boost in the engine, and this always read either 0% or 100%, and it seemed to read 100% more often than not. The scantool also had a reading for "MAP Failure" and it read 7. I believe this is a counter rather than a sensor readout but I am not sure.
Anyways, I'm suspecting that the boost reading and then the MAP sensor thing are related, and that the MAP sensor is bad or that there is possibly another sensor related to reading how much boost the supercharger is producing that is bad, and that is causing the engine to run very lean. But I really don't know much about forced induction, so if anyone could help me out with some diagnostic steps that would help me figure out what the problem is, that would be amazing
Thanks a lot!
Two trouble codes are set in the history log... one is for the O2 Sensor reading too low, and the other is for an indicated lean condition.
The readout from the O2 does indeed show it reading very low, but the reading does bounce around like I would expect and does get up to higher readings under certain operating conditions. The O2 sensor was replaced only a few months ago, and gas mileage is about where it should be.
The scantool also shows a percentage of indicated boost in the engine, and this always read either 0% or 100%, and it seemed to read 100% more often than not. The scantool also had a reading for "MAP Failure" and it read 7. I believe this is a counter rather than a sensor readout but I am not sure.
Anyways, I'm suspecting that the boost reading and then the MAP sensor thing are related, and that the MAP sensor is bad or that there is possibly another sensor related to reading how much boost the supercharger is producing that is bad, and that is causing the engine to run very lean. But I really don't know much about forced induction, so if anyone could help me out with some diagnostic steps that would help me figure out what the problem is, that would be amazing
Thanks a lot!
