Satans_Minion
New LVC Member
I have been messing with our 2005 LS for a few weeks now trying to figure out what the real issue is.
First got some misfire codes including cylinder 4 with a bunch of other codes that seem to be related to interference on that harness.
Replaced all the coils/plugs that weren't recently replaced via the extended warranty to 100k miles, car has >120k miles now.
Still runs horribly, but I am getting the passenger side o2 is stuck lean. Long term Fuel trim is maxed out, and engine calculated load is 50-60% @ idle and goes to 100% if you even touch the throttle. When it is idling you can pull any (or all!) of the passenger side coils with no effect. Check the injectors with a noid light, they are firing. Pulled the fuel rail out and checked each injector, they are spraying fuel, and there is pressure over in that rail. ECU reading 54 PSI fuel pressure.
Engine won't even rev when its in park idling, step on the gas and you get nothing.
Once you get it moving and get the rpms up it will run great above ~4500 RPM. Plenty of power runs strong will hit traction control into second gear.
Changed the passenger side primary o2 sensor just in case it was bad and still getting the same thing.
Sprayed starting fluid all over the intake, throttle body etc and no changes.
Pulled the harness from the MAF and that seems to cancel out the learned long term fuel trims when it goes into limp mode and the car actually idles nearly normal and can rev in park. MAF readings were around 2 lbs @ 2,000 RPMs. I don't understand how the o2 is reading lean when I know it is pig rich.
I have seen this problem described almost to a t on a ask a mechanic website, but there was no response from the user on the resolution. Help this thing is driving me crazy!!
First got some misfire codes including cylinder 4 with a bunch of other codes that seem to be related to interference on that harness.
Replaced all the coils/plugs that weren't recently replaced via the extended warranty to 100k miles, car has >120k miles now.
Still runs horribly, but I am getting the passenger side o2 is stuck lean. Long term Fuel trim is maxed out, and engine calculated load is 50-60% @ idle and goes to 100% if you even touch the throttle. When it is idling you can pull any (or all!) of the passenger side coils with no effect. Check the injectors with a noid light, they are firing. Pulled the fuel rail out and checked each injector, they are spraying fuel, and there is pressure over in that rail. ECU reading 54 PSI fuel pressure.
Engine won't even rev when its in park idling, step on the gas and you get nothing.
Once you get it moving and get the rpms up it will run great above ~4500 RPM. Plenty of power runs strong will hit traction control into second gear.
Changed the passenger side primary o2 sensor just in case it was bad and still getting the same thing.
Sprayed starting fluid all over the intake, throttle body etc and no changes.
Pulled the harness from the MAF and that seems to cancel out the learned long term fuel trims when it goes into limp mode and the car actually idles nearly normal and can rev in park. MAF readings were around 2 lbs @ 2,000 RPMs. I don't understand how the o2 is reading lean when I know it is pig rich.
I have seen this problem described almost to a t on a ask a mechanic website, but there was no response from the user on the resolution. Help this thing is driving me crazy!!
