po-420 on 05 Altima 2.5

[bopper]

I have a 05 Altima with the 2.5 engine, 31,500 miles, which I bought used about 6 weeks ago and have put 1200 mile on. I now have the P0-420 code, light came on 2 days ago and I had Autozone pull the code this morning.

So my questions are:

1. I'm well aware of the issue with Pre-cat failures on the 2.5 engines involving this DTC code. What change was made for the 04-05's? Could I being having a pre-cat failure? Have 05's seen this problem? With only 31K on the car, I would doubt it, but who know's?

2. The car is out of 36k/3 year Nissan coverage as it was put on the road in 1/05. Might this code be covered under the emissions coverage? What is the most common reason for the P0-420 code other than pre-cat, O2 sensor???

Thanks for any insight you might be able to give,

Chris

[mister2nr]

Go to the dealership. Cats are covered under a 8 year 80K mile warranty.

[driftingmy240sx]

p0420 is not a pre-cat code. it is a catalyst effeciency code. if the code is present you need a new cat / manifold assm. still under warranty, and if the engine blows after the cat replacement that can sometimes be covered also.

[bopper]

The dealer found the pre-cat was "coming apart internally" and replaced it under warranty. Hopefully, none or very little material made it into the engine; I'll be keeping watch for oil consumption and hope that any problem with that shows in the next 30K or 2 years while the drive train warranty is in effect.

Chris

[mister2nr]

Well yea best thing to do is keep an eye on your oil level between oil changes. If it appears to be dropping too low ex. below half and not on the dipstick around 3000 miles since the change its a good chance its starting to burn oil.