Seesnax

iTrader: (1)

Just got the MIL light yesterday, took it to Autozone and they pulled the infamous P0420 Code. Car is a 2001 20th AE with 82,000 miles, and runs great (no problems, hesitation, stuttering, etc.).

I used the sticky above on the code, and read all four slightly confusing pages on the thread-link for this code.

The main thing I got from the linked thread is that this code (for the 2001's) was covered under a TSB that will (or should) be taken care of by the dealer at no charge if under the 8 yr / 80k mile emission warranty. Problem is, I'm at 82k miles.

Several people in the thread suggested to just disconnect the battery overnight to reset the ECU, and other people said just go to the dealer and pay them ($80-$120) to reflash the ECU (whatever that means). Still others had to replace catalytic converters, exhaust tubes, O2 sensors, etc., etc., to the tune of over $1000.

I don't want to start another thread with fifty different suggestions, but I would like to first do the battery disconnect thing (this Friday night probably), then take it to the dealer for an ECU "reflash" if that doesn't work.

Does anyone familiar with this problem see anything wrong with this reasoning? Should I expect any problems doing it this way?

Thanks for any additional help you can provide.

Larrio

iTrader: (10)

if you disconnect the battery to reset the ECU, and your car is in need of a ECU reflash then the code will come back indefinitely.

I know this because i've had it happen on my 2k1 AE and my old 2k1 SE. Both were reflashed to fix the problem.

www.nissan-techinfo.com
go to inside publications - Nissan TSBs
check your year and VIN and bring it to a Nissan dealer. Good luck

maxpwr2k1

i have the same code...i went to the stealership and they wanted 200 dollars to reflash the ecu...i have 59k...i know there is nothing mechanically wrong with the car so i refuse to pay 200

woosh

maxpr1,

$200 is way too much. They just have to connect the consult II (usually a $90 diag fee if the TSB does not apply) and check if your ECU p/n is listed under the TSB. If it is there should be no other charge. If they say there is, call NNA and report them.

If they are giving you a hassle try another place. I tried 2 places before it was done. They usually say we'll check it and charge you the $90 diag fee. Yes it sounds like you could pay $90 for nothing but its a gamble you have to take or start looking at O2 simulators.

I'd say there is a 90% chance it will apply. My late 2K se qualified for it.

Here's a link to some more info http://forums.maxima.org/showthread.php?t=450450

rule da road

I get the p0420 every so often and get my CEL light on. But after about 250 miles it clears itself out. I was thinking about the O2 trick because of my ypipe because I also get about 285 miles per fill up. That would avoid buying a new O2. Not sure about the ECU flash because its expensive over here too. I just leave it alone and currently have no CEL light

Seesnax

iTrader: (1)

Update: because I am a cheap ba$tard, I ususally run mid-grade fuel in the car. Yesterday morning I filled it up with Premium, and finished driving 2 more miles to work. When I left work last night, the MIL was not on, and has not come on yet (after 30 miles home last night and 30 miles back to work this morning).

I suppose the problem cleared itself, but I have to think that it had something to do with the gas (mid-grade around here is 89 octane, premium is 91). Too coincidental.

I will keep a close eye on it, as well as the type of gas I use.

Thanks to all for your help/advice.