98 LSC running terrible, need help with codes

98LSC32V

98LSC32V

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So my car has been idleing really rough, sounds like it has cams. It stalls out sometimes when coming to a stop, when driving it feels OK, but say you are going 35mph you don't have to put your foot on the throttle, the car literaly drives itself, almost like it has 10% on the throttle. I checked the ignition, all boots and coils looked fine, changed the plugs and no difference. Smell of raw fuel at idle. Recently check engine light came on and I got the following codes:

P1506 IAC overspeed error (see P0507)
p0171 system bank 1 too lean
p0174 system bank 2 too lean

Fuel pressure is good... when the car is idleing when I hit the IAC with a screwdriver a few times it doesn't change the idle, I went ahead and took it off and cleaned it with no difference... any ideas?
 
IAC for sure is bad.
Front O2 may be bad too. I am a believer in replacing them after 50k just cause they are designed to be replaced around then. But when they go bad they command a rich condition but still read lean. So if your mileage has dropped then you should replace them as well.
 
02's were changed maybe 20k miles ago... I forgot to mention I also sprayed carb cleaner to check for any vacuum leaks and could not find any.
 
Well I sprayed carb cleaner all over the place with no signs of vacuum leak...
 
I swapped mass air meters with no change... I'm thinking possible vacuum leak from the IMRC block off plates?
 
+3, or 4 or whatever: big vac leak. its not likely that both o2 sensors died at the same time, id look real close at the big "y" coming off the driverside of the intake, and maybe block off the booster. for what your describing its a big leak not a small one like a leaky imrc plate.
 
One small thing is check all connections are plugged.
 
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