420/430 code after header install
Thread Starter
Teching In
Joined: Apr 2008
Posts: 4
Likes: 0
From: Grayslake, IL
420/430 code after header install I just installed a set of MAC mid length headers with a catted Y-pipe and my check engine light came on. I went to Autozone to have it scanned and it read the P0420 and P0430. The reason I put new headers on was b/c I pulled a 420 code earlier so I figured I had a bad cat. My passenger side O2 should be the same one I used before which wasn't throwing any codes, but I changed out the drivers side with one that came with the y-pipe ( I bought the header/y-pipe used with less than 1000 miles on it and it came with 2 02 sensors in it).
Any ideas?
Any ideas?
Highflow cats are designed for just that, higher flow, not efficiency. Some of them will throw these codes because they aren't efficient enough to keep emissions within allowable limits.
You can either get new cats (expensive) or tune out the rear O2s (much cheaper).
You can either get new cats (expensive) or tune out the rear O2s (much cheaper).
