C70 fails emissions but no CEL

Vidfix55 · Post by **Vidfix55** » 21 Jul 2018, 07:47

I got my c70 2.4 inspected yesterday and it failed emissions but is throwing no code. The reason is that it says obd comm fail reason: cat conv & O2 unsupported programming error. The mechanic asked if i had a tuning kit in it which i do not. Its all stock. The converter is new from 4 yrs ago and it never gave me issues and fixed the emission issue when it failed emissions before but the scan back then was a inefficiency code. Anyone know what this is? This is the third time its been in for emissions (every other year) but the first time ive ever hear of this.

Post by **Clemens** » 22 Jul 2018, 01:20

Maybe the cat is wearing out. Also: did they do a taulpipe sniffing test? If yes, try a different statuon. A car i had that failed one place passed in another station

Vidfix55 · Post by **Vidfix55** » 22 Jul 2018, 09:15

This is what ive found. With a scanner it says the o2 sensor is at .4v this is with the engine not even running. I pulled the o2 sensor and disconnect it, still at .4v. Hooked up my multimeter to the signal wire from the ecu and its showing .4v . Turned off the ignition, the reading drops to 0. I have bleed over from somewhere bc my understanding is the signal wire dosent generate its own power but picks up the power signal generated from the o2 sensor. Its not within the wiring harness bc there is no continuity between any of the posts