Service engine soon = Diag code P0420

I believe the TSB calls for a reprogram of the ECM. You can get the full text of the TSB from Nissan's publications site:

it's out of warranty, I'd reset it and see if it comes back.

-jim

I went to the local library today and pulled the TSB for this issue. You are correct. The TSB states...

"SERVICE INFORMATION If an applied 2000-2001 Maxima has a MIL "ON" with DTC P0420 (Three Way Catalyst Function) stored in the ECM, it may be the result of an internal ECM Program Misdiagnosis.

The catalyst should not be replaced. This bulletin provides updated ECM data to reprogram the vehicle's ECM to correct the condition."

I'm going to head back down the AutoZone and have the code cleared.

Thanks for the insight.

Patrick

I wouldn't do that quite yet ... Both the ECU and the catalyst system are covered by the Federal

8/80 Emissions warranty (check the warranty book that came with your car). Many people have had Nissan pull the code and reflash the computer for free well after the 3/36 warranty has expired. Call up your dealer, tell them the code and that you're aware of the TSB, and ask them if they'll cover it under the Federal Emissions Warranty. If they won't, call Nissan USA and complain. That should be enough. But if they try to play hardball, tell them you're calling the EPA (800 number is in your warranty book). BTW, that TSB only applies to California emissions vehicles, but I believe all 2001's are California spec.

Dan, Talked to my dealership today regarding the below issue and they indicated that this would in fact be covered by the emissions warranty if the issue was in fact as I described to them. I'll be taking it in this Saturday to have a go at it.

Patrick

I did not experience any performance issues. The car still ran like a champ.

An update: I took my maxima in last Saturday and they reprogrammed the ECM and covered it under warranty.

Thanks

Patrick