maxi-freak

Seems there's many of our cars that have set this code...grrrrr.
I took mine to the dealership and they flashed my ECU as per the TSB on that. Well..the code came back after a week or so after the flash.
Rather than pay them 75.00 for troubleshooting (they probably already know what it is), I'll break out the voltohmmeter and check all O2 sensors and ignition coils. If I find nothing wrong, then I'll take it back to them and tell them to change the cat(s), since it only has 52K miles on it.

I've read many a post on this NG about this problem, and has been helpful, but it seems that most people just start buying parts and go into plug and pray mode.

I'll post my detailed findings so as to help the other poor souls that will have/ have this problem.

zman187

its odd that your 420 went off at 52k and mine went off pretty much at the same milage......

jnovember

Same here. Ended up getting new cat at 78k. Now at 82k, no more problems. Only was able to get Nissan to pay for 50% even though I was under 80k miles. (They wanted me to pay 100%.) They insisted that part wasn't covered, even though Warranty Manual said cat converters were covered for 8/80.

maxi-freak

It's a shame that you had to play such "hard ball" at the dealership, as you did. At least you got the problem resolved.

I will definitely check everything throughly before I think that I need to go back to them for anything.