On my `01 SE I pulled a PO420 (Catalyst System Efficiency Below Threshold (Bank 1)) at 49K. I took it to the dealership and had them flash the ECU as per a TSB and knowledge from other posts here.

It's back at 51K. I just called the dealership and let them know...and I think that since it's emission testing time, I'm going to see if it passes (I reset the MIL). If it passes, then it seems that they need to increase the tolerance on that, or something. If it doesn't pass, then I wonder what's still covered under warranty (5/60,000)..o2 sensors...cat....etc.

Any thoughts or advice?

 

Any updates on your situation. My mother-in-laws '00 Maxima just got the PO420 code and the dealer is wanting to replace the preconverter AND one O2 sensor. She has had the PCM reprogrammed....

By the way, the dealer I am talking to says that the preconverter is not covered under warranty. The rear converter is covered....

Shawn
sbreeding@charter.net

 

The dealer said my cat convert was under warranty and they placed an order. they said it's on back order and dont know when exactly it will come in. .

 

Tell them to show you EXACTLY where it is written the 'preconverter' is not covered.

From what I can see in the warranty literature it clearly states "CATALYTIC CONVERTER(S)" under the warranty list for the emissions warranty. These are covered until 80K.

 

I agree but had no luck getting 100% coverage on my pre-cat replacement (which did fix my P0420 problems.. Yes I also had the ECM updated first, but problem came back). Dealer wanted over $1k to replace pre-cat. Call to 1-800-Nissan1 resulted in them paying for half. So it "only" cost me $500. Pre-cat replaced at 78k. Now at 81k with no re-occurance.

Good luck!!!!

 

WTF? Pre-cat problem?

 

Just to close the loop, I finally got Nissan to pay for this "preconverter" (as they call it). I had to kinda' get nasty with the consumer rep, but they are going to cover in full. Here's the details:

I did as suggested by jjs. I told them that the warranty covered "converter(s)" and that if this piece of tube (as she called it) wasn't a catalytic converter, then it wouldn't be priced at $1000. She kept stating that the warranty department was telling her that it wasn't covered by the 80k mile warranty. I asked for her supervisor. She said she would check with the warranty department and get back with me. The dealership called my mother-in-law at work today and said the part would be covered under warranty.

One other item that I had in my arsenal was an invoice where the dealership had cleared the PO420 back at about 21k miles and didn't replace any parts. I also notified her of this fact along with the date and mileage stating that it would appear that they had not fixed this reoccuring problem.

Anyway, not sure which did the trick, but my mother-in-law is getting the repairs done under warranty. Thanks for the support guys. I would have probably backed down without your encouragement and information about your experience.

Remember, keep those old invoices....

Later,
Shawn
sbreeding@charter.net

 

Just to close the loop, I finally got Nissan to pay for this "preconverter" (as they call it). I had to kinda' get nasty with the consumer rep, but they are going to cover in full. Here's the details:

I did as suggested by jjs. I told them that the warranty covered "converter(s)" and that if this piece of tube (as she called it) wasn't a catalytic converter, then it wouldn't be priced at $1000. She kept stating that the warranty department was telling her that it wasn't covered by the 80k mile warranty. I asked for her supervisor. She said she would check with the warranty department and get back with me. The dealership called my mother-in-law at work today and said the part would be covered under warranty.

One other item that I had in my arsenal was an invoice where the dealership had cleared the PO420 back at about 21k miles and didn't replace any parts. I also notified her of this fact along with the date and mileage stating that it would appear that they had not fixed this reoccuring problem.

Anyway, not sure which did the trick, but my mother-in-law is getting the repairs done under warranty. Thanks for the support guys. I would have probably backed down without your encouragement and information about your experience.

Remember, keep those old invoices....

Later,
Shawn

 

FYI.

If you have a y-pipe or an aftermarket cat - the 420 code should be expected and is meaningless. What it basically indicates is that the converter is not heating up fast enough.

The reason we have preconverters in the stock y-pipe is to provide emissions control until the main converter heats up. When the pre-converters are gone (just like these guys who apparently do not have ypipes) the ECM reads differences between the front and rear 02 sensors that tell the ECM that the preconversion step isn't working.

 

Glad it all worked out!!

 

I just had my ECM reprogramed for the PO420....I don't have a y pipe but why do I have the feeling this is gonna come back again


z

 

I had the code at 58k. They flashed the ECU. Came back shortly. Lived with it for a while.... SES it would go on, then off, then on again. Finally at 78k, they replaced the pre-cat. Now at 82k, no more problems have surfaced. I got 1-800-Nissan1 to pay for 50% even though they said it wasn't covered by the 8/80 Emmissions warranty.