Last year I had a hole in the pipe between the manifold and the cat....Chevy replaced it under warrt. Now a year later and 15 thousand plus miles the check eng. light is on. (Chevy says that the cat is out of Warrt.) I have gotten a huge list of codes...So, I started to work. Replaced both O2....MAF and gas cap and the light still keeps coming on. I can not get my tags because I can not get it inspected. NC wants 250.00 because I am past due, and the new code that I have now is the 420 code. Dealership wants 750.00 for a new cat.....That puts me out over a grand....And I don't have that type of money....After getting gas the car want start and if does it turns off right away. I have to give it gas until it starts then keep my foot on it until if finds its way...Any help with cheep fixes or a place to have a big party with a bomb fire and using my 06 cobalt supercharged as fuel let me know. I have been on the site all day reading post about codes and fuses....I tried the fuse thing and yea, they are all good.

 

check the state warrenty.. in IL we have a 100k 10 year warrenty on the cat.


last year the cat went out..
and then again a few months ago they thought it was the cat going again but it was just the o2's
GM replaced both of my o2's under warrenty.

 

^^^ x2 Truth there.

Emission control items (like the cat, O2 sensors, evap system, etc) are covered under the 10 year emissions control system warranty.
Hard start after fueling - sounds like the evap system purge valve is stuck open, this will give you the check gas cap message as well in most cases. This would also fall under the emission control system warranty.

Don't let the dealer hose you on this stuff....unless you broke something yourself it should all be covered.


Can't help on the late charge from the state though

 

Its a federal emissions warranty...not state and it shows when the dealer runs the cars vin in gm's system. i think its an 8yr 80,000 mile warranty on the cat provided something else didnt cause it

 

You are right it is 8 year or 80k. The problem is that I drive the **** out of this car and I already have 97k on it.....

 

420 is the code we get with an aftermarket downpipe.

Are you having a ton of codes or just the 420 one?

If it's just one then get the code tuned out.

 

I started out with O2 codes, then MAF code, then gas cap which when replaced still did not fix code and now the 420 code. (It is now hard to start and goes from 900 rpm's to 2100 rpm's for a few seconds then idels normal.) The dealership that replaced the down pipe told me today that they only warrt. for 12 months and 20k miles.....and I am passed both.