First off:
I have consulted the FAQs and I understand what the code is for. A P0420 deals with the emissions system.

Some facts about my car:
It's a 2000 with 74,000 miles and has Cali-spec emissions.

I'm taking the car in tomorrow to get this addressed, but there is a TSB for this specific problem and I wonder if they're right in shanking me for $150 to reprogram the ECU or should it be done free-of-charge persuant to the 8/80,000 Emissions Warranty. I've seen posts where people have gone to the dealer, waited thirty minutes for the techs to reprogram the ECU, and then just went on there way without having to pay a cent; and I've seen posts where people have had to pay for a diagnostic and then labor costs for corrective action.

So, how does a TSB work? Is it something that can be left at the discretion of the dealership, where they can address it free as a courtesy?

Thanks for your insight.

I've never dealt with a TSB myself, but my friend (2000 Maxima GLE) had a slipping automatic transmission for which there was a TSB (solenoid). All he had to do was bring it to a place about a half hour from here (I assume it was a Nissan dealership, though we have one in our town so I don't know why he had to go far away) and they fixed it a couple days later free of charge. It was under warranty then though, and now he has a problem with a misfiring cylinder or something that there is also a TSB for, but he is no longer under warranty and they won't fix it for free.

I am one of whom went to an Infiniti dealer and got this particular issue fixed under Infiniti factory warranty. TSBs usually are very specific about how and when they apply.

A service rep instantly knew whether the car is under factory warranty just by running my VIN #, and told me it's going to be warranty repair with no charge to me including diagnostic.

Anyway, as far as Infiniti factory warranty goes, I don't think a dealer has no discretion whether it should be charged to the owner or not. If under warranty, they just claim their work to Nissan to be paid. I mean, as long as the dealer follows the procedures specified in a TSB, they don't have to worry about not being paid for their work. But I'm not so sure about the Federal Emission Warranty, because it is not mentioned anyware in the TSB (P0420 thing).

yes this will be covered by your 8/80 warranty

the primary failed part used for an ecm reprogram is the updated ecm number - since your ecm is covered for 8/80 the repair must also be covered for that period

I think he knows this SHOULD be covered...

Thanks for your replies.

As it turned out, I got shanked for $100 for the diagnostic. I asked the advisor if it should be covered under the 8/80,000 and he seemed very confident that it should not. He said the cat is covered, but this ECU reflash and O2 sensors are not. I don't know what to think. If you all think it was wrong for me to have to pay $100, what action would you recommend to get it back?

if reseting the ECU is your only issue, I'd just do it myself... Shoot I'll charge you $50 to reset your ECU jk
Anyways you're covered if you have the 8/80 coverage.

what exactly is it they told you the car needs?

any repairs related to the P0420 bulletin would be covered on your car, as both the ecm (reflashes) and the cat are federally mandated to 8/80 coverage on your car.

if the only issue you are having is the P0420 code it shouldn't cost you a penny.