MK5 Golf GTI

All Things Mk5 => Mk5 General Area => Topic started by: chopper on May 20, 2012, 07:41:58 pm

Title: lamda sensor question
Post by: chopper on May 20, 2012, 07:41:58 pm
Ive gone stage 2+ revo on my ed30, and i keep getting a CEL, and on diagnostic it says the 2nd lamda sensor (bank 2) is reading too lean ie too much O2. Im running the APR TBE. There were no other fault codes.
I know the remap is supposed to map out this CEL but it doesnt seem to be doing it.
If i put an O2 sensor spacer on like the 42 Draft Designs O2 Sensor Spacer, should this remove the CEL?
Could the current lamda reading  affect performance?
 If it wont affect performance, will the change in the reading after fitting the spacer then feedback via the ECU to affect the fueling and performance?
I have noticed black smoke on hard acceleration through low revs too - could that be linked?
My MOT is due soon and Id like to sort the issue out once and for all.

Thanks for any advice
Title: Re: lamda sensor question
Post by: bacillus on May 20, 2012, 09:26:37 pm
Which software outfit mapped your car?
Title: Re: lamda sensor question
Post by: chopper on May 20, 2012, 10:36:37 pm
it was done by Triple 7, cookstown. I had asked them about it, and they said putting on an O2 sensor would affect the lamda reading which would have a knock on effect on the ECU which could affect performance. so they recommended leaving it alone.
Title: Re: lamda sensor question
Post by: chopper on May 20, 2012, 10:53:44 pm
could the black smoke be linked to the revo fuel setting? mine is set to 6. is that too rich?
Title: Re: lamda sensor question
Post by: muckipup on May 21, 2012, 11:51:49 pm
Some have been lucky with aftermarket down pipes not tripping the CEL due to the rear O2 sensor; I was not. Even after spacing the sensor out with an angled spacer, it still returned eventually. The only way that I could fix it was with a map that mapped out the issue. It was Revo in my case.
Title: Re: lamda sensor question
Post by: chopper on May 23, 2012, 08:36:25 pm
i have revo stage 2+, so im debating fitting an o2 sensor spacer
Title: Re: lamda sensor question
Post by: Dsg steel on May 23, 2012, 08:43:53 pm
had the same problem and i fitted the stealth 42 spacer and no more engine light for couple weeks
Title: Re: lamda sensor question
Post by: chopper on May 23, 2012, 09:35:54 pm
but, did it still come back on even with spacer?
Title: Re: lamda sensor question
Post by: Tfsi_Mike on May 23, 2012, 09:40:43 pm
It was only after having a decat I got the light.

Burnt the sensor out or the sensor died prematurely.

New sensor and apr CEL defeat code and it's not come back
Title: Re: lamda sensor question
Post by: PDT on May 24, 2012, 06:19:22 pm
Do you have vagcom? If so please check the readiness values for the 2nd lambda and post your findings.

The 2nd lambda does not control fuelling so wont be affecting the mapping. But there is a software update that should help.
Title: Re: lamda sensor question
Post by: chopper on May 24, 2012, 09:57:55 pm
Thanks PDT, ill see if i can get hold of vagcom over the weekend
Title: Re: lamda sensor question
Post by: chopper on May 28, 2012, 10:06:45 pm
i havent been able to get vagcom redone, but as i vaguely remember when i got the remap done with Vagcom at the time the mechanic showed me a lamda reading of 0.91 or 0.92. Nothing has changed on the car or with the remap since. does that value seem ok? and would a software update get rid of the cel with that reading?
Title: Re: lamda sensor question
Post by: PDT on May 28, 2012, 10:13:58 pm
1st lambda reads and supplies the ECU with data for fuelling. Second lambda is mainly for emissions, i.e checking the efficiency of the catalytic converter. At stg2+ the 2nd lambda is mapped out, so you shouldn't get any faults due to a decat/sports cat but there is a glitch with some stg2+ software versions on some ECU versions.

Spek to your Revo installer and ask them for the latest version of the map for your car, will take 15-20 mins to install and will likely solve your problem.
Title: Re: lamda sensor question
Post by: muckipup on May 29, 2012, 12:48:17 pm
^^^ What PDT said....I had the problem where my particular ECU version was one of the few that caused certain maps (even when the rear O2 sensor was supposed to be mapped out) to trip the CEL. I believe Revo are well-aware and should be able to fix that.
Title: Re: lamda sensor question
Post by: vRSAlex on May 29, 2012, 01:15:40 pm
Sounds like you have the wrong version of the file on the car.  Contact Revo.
Title: Re: lamda sensor question
Post by: chopper on May 31, 2012, 03:44:03 pm
had a chat to Revo today and explained the situation. They said there was no problem with the map and didnt suggest there was another software version. They said the problem must be a faulty sensor? Would a faulty sensor take a reading at all? i dont know much about lamda sensors , but could it have been damaged during the exhaust installation?
Title: Re: lamda sensor question
Post by: muckipup on June 01, 2012, 09:36:22 am
I would have thought that with the rear lambda mapped out, it shouldn't matter if it was faulty or even removed and blanked off. Much as I love my Revo map, there is a little history with Revo blaming hardware as an initial response.

The ECU version issue is real...I had it!
Title: Re: lamda sensor question
Post by: Thor on June 01, 2012, 04:03:50 pm
I would have thought that with the rear lambda mapped out, it shouldn't matter if it was faulty or even removed and blanked off. Much as I love my Revo map, there is a little history with Revo blaming hardware as an initial response.

The ECU version issue is real...I had it!

It's like the default response with I.T support is to switch it off and on again  :signLOL: