I have an 05 Maxima with a 100k/$0 deductible ext warranty. Just about $420 the famus P0420 come up and keeps coming back. It's eather my cats or the rear bank 1 o2 sensor taking a crap. Anybody know if this is covered under warranty? I went to the dealership and was told it would $90 to diognose the problem and only after they would be able to tell me if this is under warranty.. What's yall's take on this?
BTW, the car has 62k miles and even with this p0420 code I am still getting 30+ mpg on hwy..

 

p0420 would be bank 1 pre-cat, which are known to go bad. it is also covered under the factory emissions warranty of 8years/80,000miles. the diagnostic fee will also be waived once they verify the code and issue.

 

They told me the same thing, 90bucks to diagnosis it, after they realized it was the precat, they put me in a loaner and ordered a new part, I never paid anything, take it in, stop driving it, your slowly destroying your engine

 

How is this slowly destroying my engine...? Btw, thanks for the replies..

 

Because the bad precat could possibly be depositing particles into your engine. Not a good thing! I will let someone else chime in on the actual likeliness that this would result in damage.

 

If you search the board, many people have had the precats replaced, they break down over time and the particles get sucked back into the engine scoring the cylinder walls eventually leading to oil burning, a few here neglected it for so long they eventually needed new engines

 

Perfect time to get some Cattman headers....

 

Educate me on this.. I would have to have some kind of custom tuning for this right...?

 

Nothing like that, you just remove the stock exhaust headers and replace with the nice new ones

 

Have the same p0420 code and thought I'd revive an old thread. Anyone know if these have been consistenly covered under the EPA emission-regulated warranty?

I just bought an 06 maxima 2 days ago from the Nissan dealer here in Omaha and the next day I get the service light. I'm really hoping that it's covered under the emissions warranty so I don't have to go through the trouble of having the dealer pay for it. They're seemingly stubborn, but I just bought the car from them and it pretty much had a defect off the lot.

 

Best bet is to bring the car in and have them fix it. Good luck!

 

The cat converter is covered under the 80,000 mile warranty, thankfully. They're replacing it next week.

 

I know this is a dumb question but...are you getting a check engine light and reading the codes yourself to see p0420? And no check engine light=no codes right?

 

I got the SES light the day I bought it, so I brought it in and they told me it was the CAT converter, but wouldn't give me the exact code for some reason. So I went to Advance Auto Parts and they read the code for free. If the Service Engine Soon light is on, it's throwing a code.

 

I have an 06 Maxima SE with 71K and a few weeks back the service engine soon light came on. I had AutoZone pull the code and they said is was P0420 and was related to one of the catalytic converters. They reset the light and a week or so goes by and the light comes on again. I figured it was probably the same issue. I took the car to my local Nissan dealership and they confirmed P0420 and that a new cat was needed and it was covered under warranty. They replaced the cat and all seems well at this point. Does anyone know if the other cat is likely to fail as well? I'm concerned that it will go after I'm out of warranty. Thanks for any comments.

 

I know you all have posted all kind of stuff on this issue...look im not a mechanic and do not know about hiperformance stuff or anything related to that...all i gotta know is what do i do with this code? what do I buy? what is the most economical way to get this fixed?

 

I am going through the same problem, wish someone would have some insight on the the situation

 

Just had this this code (P0420) come up on my 06, car just passed 80k (80,141) so the factory emissions warranty no longer covers it and neither does the extended warranty. I have contacted Nissan Corp to see if they are willing to cover it, what do you think my chances are?

 

Should be covered under extended warranty...they just replaced mine for free...

 

New here, do you mean the nice chrome ones? How much do hey cost, and are they efficient? Or will a ceramic set be better?

 

The codes can be removed with a diagnosis computer, so beware when buying used vehicles or even new ones. Buy yourself a diagnosis computer and take it with you.. I take my computer with me when picking up my car from any mechanic to make sure everything is safe. never know now a days.

 

Dealers are shiesty, it mighta been just a sensor, but when they do what they want and you dont know any better, they replace anything lol, they probably replaced our sensor, or the cat and sensor, unless they looked and it was the cat that went bad which in that case I assume the sensor should of gone bad too… any one else chime in on this with more knowledge?