Lean Code Delemia

[GW2500]

Hello everybody I'm an owner of a 2010 chevy cobalt LS 2.2L . I have a lean code dilemma that I can't figure out. So this started about 3 weeks ago the engine light came on out of no where. The code read lean mixture, and suggested checking for vacuum leak. As far as the car handled the only thing I noticed was the first start in a long time the engine would crank but not catch. The next time it would start up and run fine, and the temp never got too hot, per coolant temp info.

So I personally tried with the propane technique and then tried blowing smoke w/ a cigar. Could not find anything. So then i took it to a garage. I informed the garage that the fall prior i had to get a corroded fuel line replaced. The garage that replaced it ended up making it's own line b/c the OEM wasn't in stock and this choice was cheaper. When i got it back from them it ran fine for about six months untill this lean code started. So when I gave it to the garage this time they started leaning towards fuel delivery. Also there was code for a faulty for camshaft position actuator.

So first time they replaced fuel line and evaporated return line with OEM, replace fuel filter, and cam shaft actuator.

Got it back and after 30 mins engine light came back on. Also the first start in a long time was not catching.

So I give it back, they pretty much tested every sensor and did a leak check w/ smoke machine. They also sent it to a chevy dealership to get a second opinion. They both agreed to replace fuel pump and do a fuel system clean. They also leak check for fuel tank after pump was replaced.

I get it back from the garage and after about two days, in which it wasn't driven much, the engine light came back on. It's now starting to warm up in South Carolina and the first start of the day the car catches on the first try. So I'm wondering if the slightly cooler weather playing into the choky first start. But either way I'm not sure that is going on here.

Any one can help me, much appreciated. Sorry for long first post, but figured best to get all the info out there on one post. Hoping some one has so insight for me. My only guess is maybe a nicked wire some where.

Thanks

 

[roosterk0031]

No chance you might be getting some E85 instead of E10 or E15. Mine does ok till about E50 then gives a lean code. Higher Ethanol is also harder to start when cold. Maybe try a different gas station next fill, maybe somebody mess up filling tanks.

 

[GW2500]

You know, it might be something that stupid, I'll see what happens next fill and try to avoid whatever gas station it was that either me or my wife filled up at.

Thanks

 

[GW2500]

Well sorry for the delay in response, and maybe plenty of you here already know this kind of stuff. But if your Cobalt gives you a lean code and has a choky start when the engine is cold during colder months, try putting in better gas before you start replacing things, that's all that was wrong with mine.