I have a 2010 Cobalt LT2 With the sport package. I had to change the entire exhaust about 1.5 months ago because the flange after the converter rotted out and separated. I replaced the converter and now my check engine light is on with trouble code P0420. I have attached a photo of the emissions label and thought is was EPA certified. They make these labels to complicating to read with these newer cars now. So looking at the label, is it EPA or California certified? I
Unfortunately it appears you do have a California low emissions vehicle. The exhaust shop should have been able to identify this not only with the VIN, but with the emissions sticker you have pictured.
I don’t think there will be any ill effects using the federal emissions converter. But not sure. I wonder if the PCM could be reflashed to be able to work with federal emissions. I’m sure it would have to done with a Tech II scanner, most likely the dealership would have to do it. But I’ll see if I can find out if there’s some way to not keep having the P0420 code keep coming back up unnecessarily.
You might wish to call the cat manufacturer. They may be able to offer some help. There are some known issues with replacement cats that will work out in short order...then again a poor leaking injector or misfire can melt a new cat in short order.
Any other codes?
I put the old cat back on and used a split flange connector and all is good now, no more check engine light.
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Related Threads
?
?
?
?
?
Chevy Cobalt Forum
619K posts
28.7K members
Since 2008
A forum community dedicated to Chevy Cobalt owners and enthusiasts. Come join the discussion about performance, modifications, parts, classifieds, troubleshooting, maintenance, and more!