Hi All

Audi A4 2002 2ltr Avant (ALT Engine)

Fitted a new aftermarket O2 sensor £59 OEM was £102

After a short drive threw CEL, P0130 Malfunction in circuit Implausible Signal B1 S1.

Took sensor back got and installed replacement Same as above after short drive. I have been driving the car for a week now with the CEL on. Runs Great, Better MPG. Rock solid revs at idle very smooth.

Got a chance to connect it up to vcds today. Measuring blocks 30 to 40 looked fine to me, STFT was +0.4% and LTFT was 0.0%, Excellent.

Heres the problem i think, Bank 41 first field heater resistance in ohms for B1 S1 blank, nothing in it at all. Field 3 for Post cat sensor has a value of 10 ohms in it. Gues this is the cause of my CEL

Under normal driving car seems to run great heater is working fine while driving, whats going on.

All new vacuum hoses have been fitted, new air filter, new thermostat, cleaned MAF.

Any ideas, or is it out to get the OEM sensor at £102

Thx All in advance Jim

 

I had a similar issue with my replacement O2 sensor in my 2000 A6 2.8. Installed the wrong part number and ended up getting the OEM sensor and it fixed the codes. Check the part number again and if unsure, get the OEM sensor. These cars seem to be sensitive to the resistance of the O2 heater and sensors.

 

Thx for the reply.

Yes I think the OEM should fix the problem. Had a chat with an Audi tech once when ordering a replacement parking sensor and he said stay away from aftermarket sensors as they can be temperamental on audi