So at my work we have a 2007 SS/SC for sale with 30000km and its bone stock. No tint even. Only problem is it keeps throwing a lean code for some reason. Its under full powertrain warranty still, but the dealer can't figure it out. They've replaced the injectors, MAF, and IIRC they replaced an O2 sensor too, and on the latest visit they said its cause of bad gas in the tank.

Heres the scenario when it comes on: last night I was coming home from class and I gave 'er getting on the highway and it was fine. Then about 15km later while cruising at 110km/h in 5th it comes on. Its ALWAYS a little while after I hit boost (like a decent amount of boost). I believe its hitting the proper amount as well.

The codes are P0171 (System Lean) and a new one last night was P1101 (Intake air flow system performance). It has only thrown P1101 once (last night), but every other time its P0171 that comes on. Like this morning it came on again while I was cruising to work in 5th at 65km/h and it threw P0171 twice. We've checked the intake and everything and don't see any obvious signs of a vacuum leak or anything. I've also noticed that it seems a bit rough at idle compared to my 2.2, which is nice and smooth. I think it also chugs a bit in 2nd occassionally too (but that might just be me getting used to the car lol).

Any ideas or thoughts or help would be awesome, as this is one we can't really figure out (and neither can the dealer apparently...)

 

Check to see if the evap solenoid is leaking. If it is stuck open it can cause a lean code.

 

Do you mean the evap vent solenoid at the back of the car? If so, wouldn't it throw that code too?

 

The evap solinoid that is mounted on the engine. It can leak and not cause a code.

 

The one to the right of the head? With the rubber lines going to it? Its a little plastic box right?

 

Item 531 in this picture

 

Is there any way to know for sure if its leaking? Don't want to shotgun parts at it for no reason. Also, there is a rubber line going from what I believe is the boost actuator (maybe?) to the supercharger bypass valve, and its a bit cracked. I was gonna start there and see if changing that line to one that isn't cracked to all hell will fix it.

Also, that picture doesn't help. This is the evap vent solenoid: Cobalt Supercharged Evap Vent Solenoid Valve 12597567 - Crate Engine Depot

 

Sounds like a vaccum leak.

 

Yeah I'm trying to find the source at the moment. Just replaced the cracked line running from the boost solenoid to the boost by-pass and it came back. I have a Evap purge solenoid here too that I'm gonna try based on the above recommendation (cheap part, and at this point I'm running out of places to look).

 

Reprogram the pcm to reset eveverything .
Check the injector wires near the aircon lines maybe they are shorting at boost when the engine rolls back but not blowing the fuse.
Clean out the fuel rail is another thing you can do.(I think a member named Rukkee had this issue,with crap of some kind in the fuel rail clogging the injectors.)

 

It's not injector wires because I had the code come on again after a minute and half of driving (after I cleared it) where I hit ZERO boost.

The plan now is to clean the TB (cause it always seems to be related to every problem on a delta body lol), then change the fuel filter, then bring it in to a more competent dealer. That way we know the problem is either computer related or fuel system related (but not the filter...which they would charge for lol).

We're also going to hook a wideband up to it to see exactly when its leaning out and by how much.

 

Bad intake gasket? Spray around it with some tb cleaner when its cold and watch the fuel trims