Mechanics

IDLE PROBLEMS AN RICH EXHAUST

1993 Pontiac Sunbird • 4 cylinder FWD Manual • 231,000 miles

I have a 1993 pontiac sunbird and it has been idling rough stalling at idle and have gotten a rich exhaust code also have a drop in mpg
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Bmxwayne
December 18, 2010.




What code did you get? When was the last tune up? Have you checked the fuel pressure regulator?


It was code 45 I cleared the code and it has not come back but still having problems last tune up is pretty recent how can I check the fuel pressure regulator there is no connection for a pressure gauge


Tiny
Bmxwayne
Dec 21, 2010.
45 oxygen sensor rich exhaust. It could be a bad O2 sensor. As far as the fuel pressure, you need a "T" adapter to place in the fuel line if there is no schrader valve.


Is there anyway to test the 02 sensor


Tiny
Bmxwayne
Dec 22, 2010.
Yes, you need to check for resistance.


How much resistance should there be I do have an analog multimeter
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Tiny
Bmxwayne
Dec 23, 2010.
I did more research. I want you to check the O2 sensor for a ground issue. I have attached a schematic. Here is what I need you to do. You need to check voltage to the sensor. You should get a.45 volt reference power supply from the control module. Check that. Also, with the engine warmed up, you should get between.35 and.55 voltage reading off idle.

As far as the wires you are looking for, ECM terminal C7 is a purple wire from the ECM (power supply) and C8 is a tan wire (ground). Based on everyting I read, that sounds like where the problem is coming from. Just keep your fingers crossed that it is a bad ground.


Ok o2 sensor was bad and I replaced it now I am getting code 33 map sensor circut signal voltage high/low low/high vacuum as described by chilton manual


Tiny
Bmxwayne
Jan 1, 2011.
Are you able to watch the MAP sensor's reactions via your scanner?


No I cannot it is an obd 1 system and now my car is giving me 7 codes could the prom chip be bad


Tiny
Bmxwayne
Mar 2, 2011.

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