Hi!

My car is a 04MT.

2 weeks ago, I got the CEL, and the code was 0037. We erased it from the memory, but it came again, and again. So I had to replace my rear O2 sensor.

Today, in an official Mazda service it has been replaced. I don't know why, but they unplugged my battery since the O2 sensor being replaced. When everything was done we started the car. It started smoothly - as it usually does- BUT the idle was terrible, and it died after 8-10 sec. Start again, and it happened again. The engine was warm, and the O2 sensor worked well (the CEL didn't come up again). I drove it home, I thought it might help if I drive it for a while, but it didn't...I drove it for ~50 miles, but the idle is still terrible. At least it doesn't die, but the idle isn't smooth at all, and it changes continuously (beetween ~400! and ~900). The car doesn't have any other problem, it is powerful, the engine doesn't have any bad noise, it accelerates smoothly, etc etc...

Has anybody had a similar problem? - I didn't have this problem before.

(I have a similar problem ~2 months ago, but on that time 2 spark plugs were unplugged...)

Thanks for the help guys!

 

There are two reset procedures, one for the NVRAM and the other for the KAM.

1) With the key in the off position, press and hold the odometer reset button and turn the key to on;
Continue to hold the odo button until the odometer reads "TEST" and then release.
2) Turn the key to off and repeat step one.

This will reset the entire PCM except the KAM which contains the sensor profiles amongst other things. You can reset it with the familiar procedure:

1) Turn the key to on
2) Depress the brake pedal rapidly 20 times in a row until the oil pressure gauge sweeps to halfway and back again.


You probably only need to really do the 2nd one! Reset the PCM

That might just do it.