My 00 maxima is showing a P0420. Do I just need a new converter or could it be something else?

 

I have the same problem, make sure you have a clean air filter. I have 98kmiles on mine, the dealer says I need a new Cat but the car runs great and the cat is supposed to last for the life of the car. I'm going to try to put the O2 on an extender to try and get it out of the main stream. If that doesn't work, I'll concider a o2 simulator. i will not give the dealer $2,200.

 

you need new pre cats.

sometimes you can get rid of the p0420 with a computer reprogramming.

 

He won't have precats , he's a VQ30!

 

Huh???... I also have a 00 with Cali Spec and mine has, what I thought, 2 precats (front and rear).

Black Magic, I have the 0430 code for the front precat and some people swear by simply replacing the precat and be done with it. But, from what I've read, it looks like it could be a hit-or-miss with that code, as it could be related to something else. The cause of that code has proven to be hard to pinpoint. I'm not too sure if it is the same with 0420, but I think it is related to the rear precat. I haven't serached for that code since is not affecting me but there should be plenty of information about that on these forums.

 

Or... an O2 simulator will make the 420 a distant memory for $40.

 

That is an option as is the double plug non foulers. Just replaced one of the precats on the daughter’s Max to get it through Jersey inspection. Tried playing around with the O2 sensor, but couldn't keep the light off, so as she may be selling the car in the near future we replaced the cat $275. Didn't want any comebacks from the next owner about breaking the laws by circumventing the cat or cats.

 

Aftermarket precat: $180.
Installation: 2-3 hours of work, by yourself or a mechanic. If you're willing to pay the dealer $2200, I feel sorry for you.

 

Yeah you cali specs yes, but is he a cali-spec?

 

Just replace it with a straight pipe, you won't throw codes, trust me.

 

2000 and 2001, whether federal or cali spec, are both VQ30's.

Cali spec or federal, they both have at least one precat.





Someone please correct me if I'm wrong, I could be misinformed.

 

Interesting picture. On a 2000 cali-spec, there is a pre-cat exactly where it says 'Bank 2 (B2)' - which is not depicted in the picture.

 

hey i just did a thread regarding p0420 code its in the technical service bulletin section i havent gotten replies back on how TSBs work but if there free and thats whats wrong the TSB says all it needs is a ECM reprogram!!!!! hopefully the dealership will fix it for us for free cuz ive replaced 2 of the 4 sensors and the main cat ( the dotted circle) and i still get the p420 code at times hope this helps go check it out theres so many TSBs that at least i thnk i could have quilified for ahahha

 

So (using pic fig 3) if you have the Cali and wanted to install the non-fouler for the P0420 code, would you put it on the rear sensor B1 (White)

 

TSB's are typically not free unless you're under warranty. With an 01, I doubt you are. Your dealer MIGHT do it as a courtesy if they're the ones that replaced your sensors and main cat. But then again, if they did, they should have known to reprogram the ECU.

P0420 codes are TYPICALLY resolved with a reflash of the ECU.

 

Bawney, do you know where I can get a straight pipe for my front pre-cat? I am also throwing a code and realize significant power loss, so I'm guessing a new cat is the way to go. I have non-foulers to pass inspection and they worked.

I was looking into a new Warpspeed y-pipe but I would still need the front pre-cat, correct?