P0420

[lifetrddeath]

So my CEL came on the other day... and I was like, "WTF!?" Threw a P0420, or in other words:

"Catalyst Efficiency Below Threshold (Bank 1)"

So, doing some searching, I found this great link with info about this code:

http://www.obd-codes.com/p0420

So, turns out it could be any of the following:

 - Bad O2 sensor
 - Bad Cat
 - Exhaust Leak
 - Cracked Manifold (Headers)

Or it could be as simple as a false code... which apparently this one is very common.  So I cleared it out with my scanner and have been driving for about 30 miles and it hasn't come back.  If it were an O2 sensor, at least from experience, the CEL would have come right back on.  But I'm hoping it was a fluke and doesn't show back up.

On related news, my friend pulled up in her '00 Civic while I was doing this, and she had a CEL... SAME CODE!  Haha.  I cleared hers too, we'll see if it comes back.

[danstoy]

more than likely its the cat, that code set on my 04 and the dealer replaced the cats under warranty...which i think is 8-80

[lifetrddeath]

Yeah, gotta love that long warranty on exhaust... too bad mine wouldn't be covered.

[danstoy]

it wont hurt anything, just more tailpipe emissions and the light on