alrighty, yesterday morning i stopped to fill up the cobalt, b/c of the damn inflation of gas prices, with sunoco ultra 94 (usually use 93 grade). well lastnight when i was driving home (burned already 1/4 tank) i got a CEL (constant). now i have absolutley no mods done so far ....so the only thing i could think of was the gas cap, which i checked and that was secured properly, or the fuel i put in....could the octane level be too extreme for the cpu's air/fuel mixture??

well since the car is only three weeks old i took it back to the dealership. they hooked up the diagnostics and it read some error code number stating a lean mixture. they did not know the cause but said if the car is running fine (which it is) to continue driving it and if it throws it again (CEL) to return. they reflashed the cpu, deleted the CEL and it hasn't come on since. FIRST THING THEY ASKED ME WAS "DID YOU INSTALL A K&N AIR FILTER" i said no (which i didn't) and they said good.

so do you guys think this is normal, i mean 1100 miles on the car and its' that sensitive to the mixture?? come on!! i'm already in on the group k&n purchase, but do not want to screw with the engine up let alone the warranty....but then again i guess thats the chances you take with 'hot moddin' anybody???

 

its not the gas....i only use sunoco 94...had no problems in that area....buy it at another station if u can, hate to say some gas stations may water it down, sad.......

 

It's happened to a few including me. I had a loose clamp on my throttlebody where the intake tube attaches.

 

me too.

 

will the K&N intake make the CEL or just the filter?

 

It won't throw a CEL as long as you don't over oil your filter or fail to tighten all seals on the tube.

 

well that makes me feel a little better...i'll give my intake system a thorough check, hopefully it's nothing major. the CEL hasn't come back on yet either so i guess thats good news. i still think it's a little too early to have a CEL w/o any mods yet let the bugs work out now while the GM guys are good for it.

 

GM knows about these cars setting lean codes. they have a couple of pi bulletins out about it.

one states to check for an air intake snorkel that is not fully seated to the throttle body or air cleaner assembly, or an unseated oil dipstick at the oil dipstick tube. an unseated air intake snorkel or oil dipstick can cause the engine to draw in unmetered air, which may cause a P0171 to set at or near idle.

the other one states the condition happens at highway speeds and is caused by an air filter pleat concern. if the pleats are not evenly spaced, this can cause set up an air turbulence condition that will result in an inaccurate reading from the maf sensor. they recommend replacing the air filter if the pleats are not evenly spaced. i've also heard of guys rotating the air filter 180° to fix this concern. i'd also be willing to bet that a free flowing (and properly oiled, of course) k&n filter would actually help in this situation.

 

I put on a universal K&N last week then yesterday did my 1st oil change, drove it home washed it, then started it now sets a P0171 SYS Too Lean.

 

thanks for the great "inside" info... always look forward to your posts

 

Same hear I am getting P0171 after first oil change and then washing car. I will check oil filter cap for tightness, oil dip stick, tubing for air intake. I get the P0171 during hard boot it seems.

 

I found the fix for this! Its very easy too. Remove the headlight and the bracket under the headlight to access the MAF. Unplug the MAF, then remove the 2 small philips head screws holding the MAF in place. Now I noticed the screw to practiclly fall out which led me to believe a lean condition might have been caused by air entering in around the sensor. Remove the sensor and LITELY tap it out. When I did this a small amount of dirt fell out of the sensor. Now reinstall the sensor and make sure the screws are tight.
Good luck

 

I ahve tryed this and will see if helps tomorrow. I also notested that a small amout of oil is comming in from the line going into the intake tub. Line is comming from the valve cover. I realy did not find any issues with MAF sensor or the screws but the oil does concern me. I still have yet to get the dealer to fix it. They just keep resetting the system and they also do not have a loanar car some times. I just hope they can find the solution and fix this.

 

Unless your an expert tuner, I would reccomend always bringing this car into the dealership for a CEL.
This is a harmless experiment, but it wouldnt hurt to have the car looked at , especially at this early stage.

CELs are a fact of life these days with all manufacturers. Go to any car forum, do a search for CEL or CAI, SRI and you will find them by the dozens.

 

If you have an oiled filter, then its the oil that is getting onto the MAF and causing your CEL.................

 

Up here in Canada, Sunoco pumps have a sticker indicated that their gas may contain up to 15% ethanol. I ran into a similar problem with my '03 BMW M3 which idled with a roughness etc whenever I used Sunoco hi-test. The service tech at my BMW dealer said other M3 owners experienced similar problems, and he narrowed the issue down to the Sunoco gas after polling numerous M3 owners in Southern Ontario, and related it to the ethanol content (the M3 engine management software seems to be very sensitive to the fuel composition). I haven't put any Sunoco on my '05 SS/SC, so don't know if the issue applies to it.

 

I do not have an oiled filter. The oil is comming in for the hose thats conects the valv cover to the intact to remove blowby gasses out of engen. It is in vary small amounts and I realy do not think this is causeing the problems but I just wonted to note it.

I am useing cosco and cheveron gass. I do not think there is an issue with the gass also.