So I got another CEL on my way back home. I took it to the chevy dealer, but unfortunately they were closed

However, one of the sales guys told me that I can have Onstar do a remote diagnostic on the car.

I did this and they told me it was fuel related and It is still safe to drive. I assume it's another lean out code.

The car drives fine with the CEL illuminated, anyone know if this will could cause a problem at high speeds? i.e: highway

I did try to reset it by disconnecting the NEG battery cable for 20 mins. I reconnected it and started the car with the CEL still on.

 

You did the airbox mod right?

 

Disconnecting the battery will not always clear a DTC. Even if he did the airbox mod it is NOT what is causing the MIL to come on.(see post by me in airbox mod on 10-01-05) Even stock vehicles are getting a P0171 lean.

 

I only cut some holes in the airbox. My first code was because of a loose clamp on my intake tube.

I just did a run with the car up to 110mph *legally* and it operated fine with the CEL on.

 

check your gas cap :P

 

Did that, no luck

 

I dont know what time it is by you but go to autozone and tell em to read your code. I had a code #603 something about a reset after i left the neg terminal off the batt for about 20 mins. Nothing related to lean. My airbox mod has worked out great! They where able to reset the code at autozone and it has not been back since. You did reset the computer after you made the holes right?

 

try to put more winshield wiper fluid in .... i drove around with it on for about 3-4 days ... it happened just after i ran out of winshield wiper fluid ... that is what i had to do and it took it off after about 15 min ...

 

Just unpluging the battery for 20 minutes will cause a CEL. It will set a PCM memory reset code P0603 I think.

I think after ~three cycles on and off the CEL for the reset turns off.

 

Onstar said it was related to the fuel so im sure it's not that.

That's a good point though, it seems you can get a CEL for farting too hard in your seat!

 

That is the funniest thing ever

 

Update:

CEL went out

I filled up with some 93 octane tonight and it went out. I filled it with 91 earlier in the week and I'm guessing it was not actually 91. That's what I get for trying to be cheap.

 

yeah..........thank god my 2.2L loves shitty gas

 

does it say that the ss s/c needs premium? i know it's always good to put the best, and i will once i get my car, but does it necessarily need it?

 

Recommended minimum 91 octane, which is what surprises me with the CEL.

 

usually supercharged cars take premium only

 

my buddy's GTP doesnt.......hrmmmmmm

 

How long was the CEL on for? A DTC will clear its self after 40 ignition cycles with out a fault reoccurance.

 

yeah my friend has a 98 gtp daytona edition and it says at least 91 octane. I'm going to put in at least 93 octane so i don't take any chances. Only the best for my baby.

 

In the manual, it says the Cobalt SS/SC requires 87 Octane but performs better on 91 Octane.

I use 91/93 octane on my car, despite the expensive canadian gas prices.

 

It was on for about a day.

 

DTC P0171

Conditions for setting this fault:

1. The long term FT weighted average value is more than a calibrated value.

2. The above condition is present for more than 2 minutes.


Conditions for DTC/CEL reset (note MIL=CEL):

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.

2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.

3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.

4. Clear the MIL and the DTC with a scan tool.

Notice the light should go off after 3 ignition cycles if the problem is fixed, the fault will come off the history after 40 ignition cycles.


Stuff you can check at home without a scan tool that could cause this condition:

1. Missing, loose, or leaking exhaust components
2. Vacuum leaks at the intake manifold, throttle body, and injector O-rings
3. The air induction system and air intake ducts for leaks
4. The crankcase ventilation system for leaks
5. The evaporative canister purge pipes for obstructions or plugging