Ecu fault?

[rsParnell]

I need my mind putting at ease, any advice would be appreciated.

Recently had a new clutch, de-coke and flaps removed due to an error code pointing to the flaps. While they had the exhaust off they removed the pre-cats (sounds spot on now). This was all mapped so that the ECS light would stay off.

Within 10miles the light came on again but now an error for the lamdba sensor. This has been replaced with new and all the wiring checked leaving only the ecu at fault. Does this sound right or could this be a map issue?

[RichieRS]

Can you put up the code you are getting?

Think there are a few codes that can develop from lambda faults!!.

Are you certain they mapped out the secondary o2 sensors as this will throw a code without spacers?

[Grandadg90]

Are you referring to the EPC light?

[rsParnell]

The emissions light, not epc.

Im only going on what the garage is telling me i havnt got the exact code. Im not certain about the secondary sensors, ill find out in the morning. Spacers? I dont remember anything mentioned about that

[RichieRS]

you mentioned it was mapped to avoid codes. was this to code out the intake flap sensors or the rear o2 sensors or both?

If it was just for the intake flap sensors then you will get a CEL from the rear lambdas throwing a code because you have removed the precats. some get he code, some don't. I got the CEL after about 40-50 miles after removing precats.

This will not cause any poor running or issue to the car as such, just give you an annoying CEL. You can bypass this with o2 spacers to trick the ECU or get MRC to map them out.

[rsParnell]

you mentioned it was mapped to avoid codes. was this to code out the intake flap sensors or the rear o2 sensors or both?

If it was just for the intake flap sensors then you will get a CEL from the rear lambdas throwing a code because you have removed the precats. some get he code, some don't. I got the CEL after about 40-50 miles after removing precats.

This will not cause any poor running or issue to the car as such, just give you an annoying CEL. You can bypass this with o2 spacers to trick the ECU or get MRC to map them out.

Yeah just the intake flaps i believe, never any mention of the rear o2 sensors. Ill speak to them tomorrow, cheers richie

[RichieRS]

you mentioned it was mapped to avoid codes. was this to code out the intake flap sensors or the rear o2 sensors or both?

If it was just for the intake flap sensors then you will get a CEL from the rear lambdas throwing a code because you have removed the precats. some get he code, some don't. I got the CEL after about 40-50 miles after removing precats.

This will not cause any poor running or issue to the car as such, just give you an annoying CEL. You can bypass this with o2 spacers to trick the ECU or get MRC to map them out.

Yeah just the intake flaps i believe, never any mention of the rear o2 sensors. Ill speak to them tomorrow, cheers richie

No probs buddy. Good luck and let us know what they say. If you can get them to write down the codes or give you a txt file then that will help.

[rocket1]

hi mate,
did you get the work done locally. as mentioned i think you need lambda sensor spacers once youve removed the precats. been thinking of doing similar with mine and a deflap. be interesting to compare the 2 cars to sse the difference.

[rsParnell]

you mentioned it was mapped to avoid codes. was this to code out the intake flap sensors or the rear o2 sensors or both?

If it was just for the intake flap sensors then you will get a CEL from the rear lambdas throwing a code because you have removed the precats. some get he code, some don't. I got the CEL after about 40-50 miles after removing precats.

This will not cause any poor running or issue to the car as such, just give you an annoying CEL. You can bypass this with o2 spacers to trick the ECU or get MRC to map them out.

Yeah just the intake flaps i believe, never any mention of the rear o2 sensors. Ill speak to them tomorrow, cheers richie

No probs buddy. Good luck and let us know what they say. If you can get them to write down the codes or give you a txt file then that will help.

Its back in there monday, he said it was 'lambda sensor bank 2.....' he couldnt remember the full code and it was all mapped out for the pre cats. Ill get the codes monday.

Be interesting to see if there is much difference rocket, it definitely sounds better without the pre-cats

[audi_do_dat_den]

Definitely post up the results mate, this is one of those topics that others will benefit from.... what a good forum is for essentially.

I would put money on the sensors still being active.... although the pre-cats are more an emmissions legislation item, if the ecu is still seeing their response and trying to deal with it, it will sample a set number of responses and then flag an error and fiddle about with fuelling/timing in the process.
Mapping out the pre-cat sensors wont fail an MOT and will also tell the ECU that all is well....