I replaced my 02 sensors. Do I have to reflash the ECU?

 

Most likely yes.

Did you clear the CEL? If not, try disconnecting the battery overnight and see if it comes back. If it does, you'll need the reflash.

 

Does this mean that if i did change my o2 and my light still comes on, its just a glitch and i still have a working o2? I had my new o2 since last january (03) but the light has been there since feb (03). Or did i just mess up another o2 sensor?

 

Yes, if you cleared the error code by either A)using an OBD scan tool or B)leaving the battery disconnected for 24hrs, after replacing the 02-sensor and the code/light came back, then you'll have to get the ECU reflash from the dealer to desensitize the ECU monitoring of the cat.

Honestly, it has nothing to really do with the 02s, it's the catalytic convertor. As the catalytic convertor ages, it acts differently and the ECU sees this by comparing your front to rear 02s. You replace the 02s, but that doesn't fix what the ECU thinks the cat should be acting like.

You didn't hurt the 02-sensor, you just need the ECU to be labotomized and taught what a 60K mile catalytic convertor acts like.

 

All those elctronic gimmick make me sick!!

My old ranger dont even get a o2 sensor and just work fine!!

ressetting the ecu, clear the code and should be ok afterward!

 

I have a bad O2 sensor and my CEL is on.
Alex, after I replace it can I got to Autozone to have them clear the CEL with their OBD thing?

Thanks

 

All these SES lights and CEL lights make me sick! This is rediculous!! Whats the problem.

This was just a vent.

 

I replaced both of my front O2 sensors last night, pain in the a**, and my car is working "better". It is no longer stalling at stops or hesitating badly, but my power is still not all there. I left my battery plugged for 11 hours, and my SES light is no longer on. I'm going to ride on it for a couple of days and see how it does. I might have to replace my MAF too?

 

Yes, but I'd try just leaving the battery disconnected overnight to save you the trip.

If it's truely the 02-sensor, your CEL stay off, if it comes back, you might be in for a stealership experience.

 

Apparently my 02 sensors were not the only problem. My car runs "okay" if, and only if, I warm it up for several minutes before I start driving it in the mornings. I have no acceleration through the power band, above 3500-4000 rpm. I am so sick of this shtuff. I am going to buy a MAF and Ignition Coils today and replace everything that seemingly has ever caused 2000 Maxima Owners problems. If that doesn't work, please check the For Sale Forum for a steal on my car.