P0420 Code

[dcountiss]

The Service Engine Soon light came on a couple of weeks back on my 2000 Tahoe, 5.3 L V-8. Took it to AutoZone, got a P0420 code. Says the Cat is bad, possibly due to one of three things:
1) Engine Misfire / Running ROugh
2) Large Vacuum Leak
3) Engine Oil Leak into Exhaust.

My question is this, could it be that the Cats just need replaced? I've got a little over 200K miles on the originals. And should I go with direct fit, or weld a couple of universals in place? Thanks.

[maintainin76]

Originally Posted by dcountiss

The Service Engine Soon light came on a couple of weeks back on my 2000 Tahoe, 5.3 L V-8. Took it to AutoZone, got a P0420 code. Says the Cat is bad, possibly due to one of three things:
1) Engine Misfire / Running ROugh
2) Large Vacuum Leak
3) Engine Oil Leak into Exhaust.

My question is this, could it be that the Cats just need replaced? I've got a little over 200K miles on the originals. And should I go with direct fit, or weld a couple of universals in place? Thanks.

Have you had any of those three happen to you? Seems to me 1 and 2 on your list would likely throw their own code and 3 would probably cause some fairly obvious smoky exhaust. If you havent had any of these happen, I dont think they would cause the cat to fail. But yes you do have a bad cat. If you have under 80000 on the truck you can get it replaced at the dealer for free. There is a 8year/80000 mile emissions warranty on cats.