HELP !! 02 sensor re-occurring fault codes 0130 & 0135

[Dirtydave]

Hi guys

Vauxhall Astra H VXR - stage 3 Rabbid remapped 4 weeks prior to fault occuring

urgent help required as we are baffled:

car threw the EML light on and 0130 and 0135 codes about a month ago, I had a split downpipe at the time so put it down to that. Replaced exhaust system with a new Piper 76mm system and fitted a new front 02 sensor., cleared codes and drove the car.

15 miles later the EML and codes re-appeared - 02 sensor bank 1 sensor 1 range/performance and bank 1 sensor 1 02 sensor heater malfunction.

changed the cheepy sensor i bought and fitted a genuine Bosch one

cleared the codes, ran live data and could see both front and rear 02 sensors working as they should be.

drove for 15 miles and sure enough the codes were back. Weve gone through the wiring and all seems to appear fine. tested the new sensor on a multimeter and again all is fine.

this morning cleared codes, I ran live data again and drove for a few miles, sensor was working as it should. when i stopped I had no EML light but checked codes again and the two codes were stored.

so in brief, for a short time the sensor will work as it should and the ecu is taking readings from it but at the same time storing fault codes as it thinks its faulty.

I'm currently starting to think the ecu might be at fault but thought I'd ask you guys first.

Any ideas would be gratefully received

Dave

[Andyb712]

Did you have exhaust fitted after the map or before?

[Dirtydave]

It was mapped with a remus full decat system and the fault occured with that exhaust still fitted, I used the downpipe split as a good excuse to upgrade the exhaust.

[Dirtydave]

Anyone??? Any ideas??

Spent this morning back live/positive feeding from the engine loom o2 sensor plug to the ECU plug, read the wiring diagram and all worked at the ECU plug as it should. Appears I have no broken wires.

Cleared codes again, ran on idle, then fast idle whilst reading live data, front 02 sensor appeared to be working, got engine hot, didnt drive it, front sensor reading were fluctuating up and down, fuel mix switched between rich and lean, both 02 sensors switched between active and inactive.....all seemed fine. Switched off again, scanned codes and got 0130 range/performance again.

Fitting another 02 sensor tomorrow- an NGK one this time just to rule It out!!

If it doesn't work am I looking at an ECU fail???

[corsavxr13]

I had this code on my astra vxr turns out my sport cat had failed and the code hasn’t come back since getting a new sport cat

[Andyb712]

Is the piper also a decat like the remus was ?

If so the map may need tweaking due to the extra reduction in back pressure compared to the remus

[Dirtydave]

Yes the Piper is a full decat system, I'd agree with you however the fault occured when the remus was still fitted.

Also why would it once the codes are cleared sat on idle with no throttle show on live data that the sensor is working but still log the same 0130 fault code

[Andyb712]

Strange one that mate what code reader are you using?

[Dirtydave]

I've been using a snap on scanner and an aural scanner, both show the same results and show the same live data readings - out of ideas now. Probably gonna send the ECU away to be checked

[Andyb712]

It could be the decat causing it, was it mapped in for sensor parameters

You could be getting the no plausibility error between sensor 1 and 2

Do have the Eml cheater spacer for sensor no2

[darkrealm]

You may need to fit an o2 spacer

[w20adm]

It's funny how some cars throw up eml codes with a new exhaust and others don't. Mine never did at any point. I still fitted a spacer though to make room and make it easier when I replaced senor no.2