please help me!!!
Thread Starter
Intermediate
Joined: Aug 2002
Posts: 36
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From: tyngsboro mass
please help me!!!
91 L98 w;manual.. leans out to the piont it wont stay running, had a code 44 re placed o2 sensor, fuel pressure is fine at 39 when running, new plugs cap rotor wires, but can tell by sound and throttle response it's still way too lean afraid to run it for long now so i don't burn a piston.. does anyone have any idea what to look for now? i have been working on cars for 30 yrs but this thing is baffling the heck outta me??? it starts just fine but it isn;t right, thanks in advance
Thread Starter
Intermediate
Joined: Aug 2002
Posts: 36
Likes: 0
From: tyngsboro mass
plugs were white as new even after about 15,000 that was one of the reasons i knew it went lean i thought it leaned out when it went into closed loop but now i can tell its lean right from a cold start up in the morning.
Team Owner
Joined: Dec 2000
Posts: 90,675
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From: SE NY
Cruise-In II Veteran
The code 44 is caused by the ECM seeing the O2 sensor reading below .2 Vdc for 50sec while in closed loop mode.
The problem can be due to:
-faulty O2 sensor
-faulty wiring from the O2 sensor
-the AIR diverter putting air into the exhaust ports
-a faulty MAF sensor (but you have only a MAP, so I don't know if that could be an issue or not)
Check to see if it is going closed loop, using the field diagnostic mode described on my site. If it is, you can disconnect the O2 sensor and see if it goes open loop.
You can also disconnect the AIR tubes to the exhaust manifold to eliminate that possibility.
If all else checks out ok, replace the O2 sensor.
The problem can be due to:
-faulty O2 sensor
-faulty wiring from the O2 sensor
-the AIR diverter putting air into the exhaust ports
-a faulty MAF sensor (but you have only a MAP, so I don't know if that could be an issue or not)
Check to see if it is going closed loop, using the field diagnostic mode described on my site. If it is, you can disconnect the O2 sensor and see if it goes open loop.
You can also disconnect the AIR tubes to the exhaust manifold to eliminate that possibility.
If all else checks out ok, replace the O2 sensor.
Team Owner
Joined: Sep 2003
Posts: 88,393
Likes: 2
From: eville in
Originally Posted by 65Z01
The code 44 is caused by the ECM seeing the O2 sensor reading below .2 Vdc for 50sec while in closed loop mode.
The problem can be due to:
-faulty O2 sensor
-faulty wiring from the O2 sensor
-the AIR diverter putting air into the exhaust ports
-a faulty MAF sensor (but you have only a MAP, so I don't know if that could be an issue or not)
Check to see if it is going closed loop, using the field diagnostic mode described on my site. If it is, you can disconnect the O2 sensor and see if it goes open loop.
You can also disconnect the AIR tubes to the exhaust manifold to eliminate that possibility.
If all else checks out ok, replace the O2 sensor.
The problem can be due to:
-faulty O2 sensor
-faulty wiring from the O2 sensor
-the AIR diverter putting air into the exhaust ports
-a faulty MAF sensor (but you have only a MAP, so I don't know if that could be an issue or not)
Check to see if it is going closed loop, using the field diagnostic mode described on my site. If it is, you can disconnect the O2 sensor and see if it goes open loop.
You can also disconnect the AIR tubes to the exhaust manifold to eliminate that possibility.
If all else checks out ok, replace the O2 sensor.
