MellowCat

My Reset tool doesn't tell me where the O2 Sensor is located. Here is what I googled: P0140 O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 2) I seem to have alot of O2 Sensor issues. At one point the dealer said all of the O2 Sensors would go. I added up over $600 to replace them! I've already spent almost a Grand on electrical parts this year! Any help would be appreciated! Scott

any idea which O2 Sensor I need to replace to cure this issue? I sure am sick of resetting codes on my Pathfinder! Thanks< Scott

I thought the code reader strictly cleared error codes, I didn't think it would clear learned settings? Disconnecting the battery doesn't clear error codes, tried that in the past, hence the purchase of the reader.

Can anyone tell me the proper procedure for reseting my ECU? I want it to "re-learn" its programing since replacing my MAF. I tried googling this but didn't find anything trustable. I have a OBDII code reader/reset tool if that helps any! Thanks, Scott

I just did this to my 2001 Path SE 3.5. Works Great! I forgot how much power I had lost with that bad Mass Air Flow Sensor. By the way, when my MAF died it never threw any codes, the engine just didn't have its full power, and it often missed above 3200RPM. Thanks for saving me $300! Scott :bow:

got it

Thanks, thought so. I must admit, my 3.5 has not been nearly as trouble free as the 3.3. Somedays I wonder if the extra power is worth all the trouble. Also, the gas milage is horrible.

Does the 3.5 motor need belts too, or is it Chain now? I know the 3.3 motor is belt.

REVO's Best tire on an SUV ever.

Thanks for all of the replies. I normally would do this repair myself, but didn't have the time honestly. Parts ran about $85 per coil, I replaced all 6 of them. The codes I read intially were: P1320 P0301 and the final time, when I quit driving the car(it was shaking and missing too bad!) P1320 - ignitor circuit malfuntion P0301 - missfire detected P0140 - O2 Sensor P0130 - O2 Sensor Resetting the codes each time was a temporary fix. As the problem got worse the fix would last for less and less time. Anyone buying a higher mileage 3.5 should figure this repair(and O2 Sensor replacement) into their costs of ownership. Any other known issues with 2001 or 3.5L engine I should know about? My transmission is slipping out of gear at times too, I understand this is a known issue too and my TCM(transmission control module) will need to be replaced. Anyone been through this repair, could I do it myself? Thanks for the replies, MC

YES, mine was off till I got new tires. Right around 5mph too. The stock tire is a really weird size, I wonder if Nissan messed up.

any other R50 owners with the 3.5 engine had to replace your coils? I'm having issues with the motor running real bad, poping the check engine light(sometimes even flashing). I read the codes and reset. The car then drives fine for a day or so then I repeat the process. The dealer tells me I need the coils(and possibly the O2 sensors) replaced for $650. Does this sound familier to anyone? By the way, the rear O2 sensors run $450 installed......this is like 10 times more than BMW charges! I love my pathfinder, but with $1000 worth of electrial work I feel like I'm driving something German.... MC

Ok, I lied! Sorry! My tires are 255/70/16's, not 75's. The 265's hit bad.

16 city 18 hwy all year around. 2001 3.5l SE. I just switched tires awhile back to a AT style tire. I think its hurt alittle, but not huge.

I got 255/75/16's Dueler Revo AT's to fit just fine with no rub. Wanted the next size up but they hit.