SlimJ GBR

Hi guys,

Over the past couple of weeks I've had the CEL come on and it won't stay cleared once reset, the light normally comes back on with the P0131 fault code. General car running has been fine, no hesitations when pulling away and fuel economy not too different to normal (220-240 miles to a tank). However, when pulling up to a junction or from revving the car while stationary out of gear, the revs drop to almost stalling point before recovering although the revs sometimes bounce around between 500-800rpm until stabilised. As the idle issue has coinsided with the CEL I'm pretty sure both are associated.

My car has a decat, but no fault codes have been reported with regards to the decat.

Now with the P0131 I think I need to replace the primary sensor before the cat, correct? I replaced it a couple of years ago with a cheapo one which has lasted well, so I'm probably looking at this one from Euro Car Parts.

Typically my MOT is due on Saturday so need to get the cat back on and a new sensor otherwise I'm guessing my car will fail on emissions.

Nottm_S2

Hmmm. Probably will fail.

richmc

P0131 Primary Heated Oxygen Sensor (Primary HO2S) (Sensor 1) Circuit Low Voltage

Yep fail.

Have a look at the tech FAQ there is a whole section on poor idle and stalling.

Dixon Motorsports

You should mention MOT to me last time when you were down here, I have someone do this for us.

Yes we checked your check light last time and it was showing your O2 sensor, we cleaned them both but it didn't help, best to get it replace.

SlimJ GBR

Thanks guys, ordered a new sensor from Euro Car Parts and shall fit this before the MOT on Monday. I'll also check the FAQ's should the new sensor not cure the rough idle.

Dixon, I'm a sucker for saving money so I can't turn down a £25 MOT even if it means removing the decat! Thanks for checking the sensors, the one on the front was a replacement that cost about £12 IIRC, so it wasn't likely to last forever, so I'll be swapping this one over with a Bosch.