Well first off my check engine light has been going on and off every week for the last 3 weeks, I havent noticed anything wrong or maybe there is and im missing it haha. But also ive noticed that it seems like the mileage im getting is almost as bad as my last suv, it was a blazer. I fill it up drive around for a little bit to do some things and what not and im down a 1/4 of a tank. Has anyone else had this problem or heard of it??? Thanks in advance.

 

Do you have any mods?? It also depends on how you drive. I know i drive my car like i stole it and get an average of 16 mpg

 

Nope no mods and for the most part dont drive like a maniac, sometimes ill let lose but i dont thinl enough to drop so much in mileage.

 

It could be something like the gas cap causeing the CEL, as for the poor milege, In the winter the gas is crap compared with summer gas so that may be it. I would suggest going to Auto Zone and getting the code read and then come back here and tell us what the code was (ex. p0171)

 

Hmm all righty well the cel is off again so it might be a little bit haha but thanks alot for the help.

 

Well... My CEL is almost constantly on with the code, P0442 (small evap leak). They have replaced the gas cap like 3 times, and eventually they contacted GM and apparently there is an issue going on which has not been resolved, although supposibly there is no negative effects... but when they figure it out, supposibly there's going to be a recall.

 

Wow I have a 2007 ss sc with all kinds of problems. My car randomly turns off and will not start for 4 mintes or i have super loss in power for like 5 miuntes while driving then i get a check engine light and the car start runing good again. Its really pissing me off I have only 900 miles on the car. O and my car pings like hell.
Dealer said there is nothing wrong i just keep stallling it and I can not drive.
I pointed to my last car which is still on the lot and told them I can out drive any them anyware ant time. I traded my car in it was a 2004 GTO STS turbo 500 HP 6 speed.

 

Damn ur last car must have been a beast. This is the first problem ive had with my car, like i said nothing noticeable its just annoying that the cel keeps coming on. Sorry to hear about the bad luck with the car so far. Question though why'd u trade in ur last car? Must have been a big step down in power.

 

no...ive seen ss's smoke gtos; there was a vid on here before lol, maybe that made him change his mind. Stevo, I dont have the same car, but I have the same problem however. My CEL is on constant (could be because I have a sunfire). Although I have the M45 sc, MY cel light went on asap after I got the SC and rammed it; it turned out to be my exhaust temperatures being too high after I got it read. This supposedly, screwed up my 02 sensor. As for why the temperatures are too high, I dont know other people have kits that are fine. But my gasmileage is bad. Really bad, in fact to give you an idea, I used to fill 20 bucks and get 300 km, now with the SC and same driving behavior I pay 20 bucks and only get 100km. Im assuming we have the same problem! lol

 

yea my gto was fun but it had a lot of problem with the breaks the rotors on my GTO keep warping every 10k and the dealer could not get the aliment right on my car and my tires would wear out every 10k so after 40k I was done with the car plus I think I broke the rear end it would not lock any more and only spine one tire.

 

Hmm thats no good well good luck with ur new car and thanks to everyone for the help still havent gotten it looked at but i will on thursday and ill let everyone know.

 

So the code was p0171, something about my exhaust or o2 sensor haha i forget already, but i got an appointment with my dealer i just wanted to know if anyone else had this and what was it or how was it fixed?

 

If im not mistaking p0171 is the lean code. Wierd to get that on a stock car.

 

Ya thats wut i thought cause alot of the people on here talk about getting that on a car with stage 2 i believe maybe im mistaken.

 

The P0171 is the most common CEL on the Cobalt. Its the Fuel Trim System lean indicator. What it means is the O2 sensor is reading oxygen, and forcing the fuel system to add more gas. The CEL is caused because the amount of gas being injected doesn't match the amount of air entering the engine being read by the Mass Air Flow sensor in your intake.

It can be caused by a dirty or bad MAF, an intake system leak (allowing air in downstream of the MAF), or a bad O2 sensor sending incorrect readings.

Our cars are very MAF sensitive. It's the biggest issue that people with aftermarket intakes have. It's not a terrible problem, the ECM compensates and your engine continues to run fine. But the ECM does see that something is not reading right or leaking.

You however are also getting bad mileage as you say. So you might actually have an issue where you are running far too rich, but that car is seeing the opposite. So have it checked.

If you are under warranty, leave it alone. If not and you want to check it out, do this. Check your intake to make sure its on snug and not loose. Then check the MAF. I hate to recommend that because checking it is more likely to result in making it worse. It's a touchy little thing. Unplug it in, remove it from the intake, and see if it got dirty. Don't touch it. Put it back in and you should be fine. The O2 sensor is the least likely culprit and it would probably be accompanied by other CEL codes to let you know there is a problem.

 

Thanks alot! That gives me a good understanding of the problem