Help on 2002 LE pathfinder

[240sxTurbo]

Well with 80K on the dial I decide to go ahead and change a few things on the SUV. I did belts, plugs, air filter and fuel filter. Install went fine no problems that I noticed however now the vehicle has a strange idle stumble, and at anything over 25% throttle(load only) the car surges. I verifed I installed the fuel filter the correct direction(event swapped in the old one to be sure), next I pulled every plug and each of them looked identical and smelled identical. Lastly I had my wife start the car and with it idling I pulled each coilpack connection and the motor would start to shake and stumble so I know all 6 are firing. I'm actually kinda stumped on this one. I think it "could" be a coil pack however I'm unsure of how to test those out. I replaced with factory NGK plugs with proper gap(checked) and so forth.

Thoughts suggestions and other ramblings welcome.

[240sxTurbo]

Problem discovered.....it was the new plugs. The NGK plugs that came in the car were the exact same part # as the replacement except the ones in it are R. I'm pretty convinced the R is for resistor type plug and the ones I got where not. I will be returning to get the proper ones. I'll report back my findings.

[NISTECH]

how did ya like doing plug number 2 on the left bank he he. They made that maintnence fun huh? incedentally your not due for plugs on the pathy till 105k btw.

[240sxTurbo]

Well I have managed to get good at it....LOL. Turns out I had a CEL come up which was mis-fire #1 cylinder. To bad for me that I didn't keep the order of the new plugs when I pulled them. I'm getting another whole set from the advance store so this time hopefully I'll get the ones that haven't been dropped yet. I have heard rumors (from local master techs)that as the plugs age they cause a slip pinging problem on the VQ35's that in turn will burn the cat out of the patty so I'll go ahead and swap about 20K early.

[NISTECH]

Odd I havent heard of that problem yet. Being I am nearly a master tech for nissan i thought I might have.

[240sxTurbo]

Local guy is shop foreman for them says he has started seeing something similar. The cat is like $1200 vs $50 for plugs so I can't really go wrong with that. Anything else you seen while doing service on pattys.

[NISTECH]

I have seen a set of cats go bad, but it was determined to be due to a lean condition from o2 inputs. incedentaly the O2's have problems as well. More so with the rear O2's and the rear O2's are not used for fuel control.I have also seen a problem with the VTC sensors and solonoids, as well as with the airflow meter which can also take out a cat over the long term.

By the way I too ran a nissan shop for the last 2 or 3 yrs. I just recently changed jobs though to work closer to home and decided to pass on the runnin the shop thing for awhile. Its a major headache holding other techs hands plus handling new car customers face to face when someone else has pissed them off, or trying to get a supervisor to do his job correctly so the tech understands what the hell the problem is when his write up isnt even close to what the customers concern is or......ect ect ect.

Ask him about that part of the job..lol

I would like to know how many cases hes seen of it and I really wish you were able to get me some of his technical diag info as it could be useful to me in the future knowing this is occuring. I have learned things at nissan regional offices about certian types of failures being more common in certain parts of the country but not common in other parts.

Dont go out of your way to get it or inconveince him to get it but it would be cool if you could.

[240sxTurbo]

I have already had a code flash on the ECU for the issue with heating the O2 element to quickly thus cracking however I have yet to have any of the other issues. He basically stated that there was a lean condition involved and noted the plugs were the cause and it would in turn burn out the cat. I'll see what kind of info I can get out of him and let you know.

[AuburnRyan]

How hard were the belts? Mine need changing and the space looks tight? Is it a simple loosen bolt, move pulley and slip off/on belts?

i.e. I've done my 240sx belts.

FYI there is a TSB out by nissan to reprogram the ECU for the O2 sensor heat up.