99 SE 5-speed, 150K miles... I just changed my fuel filter, and after starting the car the check engine light comes on... I hooked up my scan tool, it showed 0, no codes found... I reset it, drove around the block, light stayed off... Next morning same thing, start the car, check engine light, no codes. I checked all the wiring, etc, around where I was working, I don't see anything wrong... Could there be some code that my scanner is not finding? It is made by Stinger, I got it about 5 years ago... I am able to reset the light, so I know the scanner is linking to the ECU...

 

Autozone guy was able to scan out P0135 and P0155 (these are generic, not sure why my scanner was not pulling them)... Now I wonder if two O2 sensors would fail at the same time? I will check the wiring first I guess....

 

If you had a more detailed scanner you could check the graph of the 02 sensors and see if they are working..

 

Give it some time....you jus changed the fuel filter and and gettin different fuel characteristics/emissions. THe old sensors are used to worse conditions. They will take some time to adjust. Same thing happened to me when i finally replaced a busted muffler. Once the car got used to the newer component..check engine light went off.

 

Thanks, I think I will wait for a few weeks.. Maybe the fuel pressure/mixture is changed now (from changing the filter, which had not been done for 90K miles, my bad), and the ECM needs to relearn things... Car seems to run fine....

 

Yea jus wait 2000 miles or so.

If the problem persist, see if there is a way to clean them or spray them with somethin like MAF cleaner. IDK so ask the org first. Maybe someone else knos

 

FWIW, when i put my Z32 fuel filter in, i disconnected my battery overnight and had no problems. i think you should try that. resets everything basically.

 

newbie here . . . Do maxi Ecu's have the blinking lights on the side ? some cars do and you can retrieve your code that way. . . ie long blink light equals 10 place short blink equals 1 place . . 2 long and 4 short is code 24 and so on . .just wondering . . .

 

Does anyone know where to get OEM part numbers for the 2 front O2 sensors? In case my problem persists and I have to replace them... I tried various web sites that sell these, but I think there may be some difference between 1999's made through 5/98, and those made from 6/98 - 3/99, as some places show that... My car was made in 9/98, so I am afraid if I order sensors I may not get the right ones... Oxygensensors.com has a cross reference to OEM part numbers... I tried courtesy nissan online catalog, but they show what appears to be a stock or sku number, which I don't think is the actual part number (the prefix is the same, but the suffix looks like a catalog number and not a part number)...

BTW, car is Calif emissions.....

 

D'oh... I just found what happened (I am an idiot). When I pulled fuse 32 to disable the fuel pump (to change the fuel filter), I placed it back into slot 30, which is normally empty. When the car would not start, I then pulled fuse 31 (not 30) and moved it to 32 (car started, but then check engine light came on right away because the heater circuit was disabled for the 2 front O2 sensors). I drove this way for a week before I found the missing fuse... After placing the fuse into 31 and resetting, the car started OK, but now is stumbling during warmup, and the codes I get (obtained by the flashing light method) are 0412 and 0509, which point to the front O2 sensors again, but now a 'high voltage' problem, not the heater circuit... I wonder if the sensors are toast now? I'll probably replace them anyway, they are original with 150K miles....