Emissions light after cat delete

4.2 V8 32v Naturally Aspirated - 414 bhp
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moondog01
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Joined: Sat May 09, 2015 2:36 am

Emissions light after cat delete

Post by moondog01 » Thu Aug 29, 2019 3:50 am

Need help with orange emissions light on dash which has come on after cutting out rear cats and exhaust work. Local garage (not Audi) deleted light but it came on again. They suggested soldering a resistor between appropriate wires on O2 sensors to fool computer into thinking emissions OK. Anyone tried this? Or any other suggestions welcome.

The Flying Kiwi.
:kissmyrings:
'06 RS4 B7

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Dinosroume
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Location: Greece

Re: Emissions light after cat delete

Post by Dinosroume » Thu Aug 29, 2019 9:37 am

moondog01 wrote:
Thu Aug 29, 2019 3:50 am
Need help with orange emissions light on dash which has come on after cutting out rear cats and exhaust work. Local garage (not Audi) deleted light but it came on again. They suggested soldering a resistor between appropriate wires on O2 sensors to fool computer into thinking emissions OK. Anyone tried this? Or any other suggestions welcome.

The Flying Kiwi.
:kissmyrings:
Just get a stage 2 remap to fool the rear O2 sensors.
I'm planning go decat in my rs4 with an H or X pipe and stock rear backboxes and REVO stage 2.
You need to delete the rear lambdas or a software that avoids rear lambdas (stage 2 remap)

Dinos

Rick_RS4
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Re: Emissions light after cat delete

Post by Rick_RS4 » Thu Aug 29, 2019 10:57 am

Get 2 lambda bosses that extend the lambda away from the flow. I have the 90 degree ones

Daytona
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Re: Emissions light after cat delete

Post by Daytona » Thu Aug 29, 2019 1:34 pm

+1 for spacers, I had mine on for ages before I had a remap and the light didn’t come on once.
I’ve still got them if you’re interested?

moondog01
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Re: Emissions light after cat delete

Post by moondog01 » Sat Aug 31, 2019 7:26 am

Thanks for the help guys. I think I'm going to go with the remap option. Spoke to the tuner, who said they expand the range in the computer to effectively delete the fault and the sensor will then read correct to the cpu. A map will give me the option to improve performance as well and I'll get it on the dyno for the first time.
'06 RS4 B7

James1984
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Re: Emissions light after cat delete

Post by James1984 » Sat Aug 31, 2019 5:37 pm

How long did the light take to show up?
2007 B7 RS4 Saloon, Phantom Black, Forge Oil Cooler Kit, custom home made air feed, H&R Coilovers, H&R anti roll bars, 10mm H&R Spacers, Milltek decat downpipes, Milltek Non Res Valved Exhaust, Reyland Motorsports front & rear discs with Hel braided Hoses, full underbody overhauled inc powdercoated subframes and arms, 034 solid subframe bushes and every joint, arm or bush replaced.

moondog01
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Re: Emissions light after cat delete

Post by moondog01 » Sat Aug 31, 2019 9:21 pm

James1984 wrote:
Sat Aug 31, 2019 5:37 pm
How long did the light take to show up?
About 50 miles of travel after exhaust work from memory.
'06 RS4 B7

James1984
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Posts: 309
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Re: Emissions light after cat delete

Post by James1984 » Sun Sep 01, 2019 8:41 am

moondog01 wrote:
Sat Aug 31, 2019 9:21 pm
James1984 wrote:
Sat Aug 31, 2019 5:37 pm
How long did the light take to show up?
About 50 miles of travel after exhaust work from memory.
Thanks, I have a full decat and mines still off, only been running for a few days
2007 B7 RS4 Saloon, Phantom Black, Forge Oil Cooler Kit, custom home made air feed, H&R Coilovers, H&R anti roll bars, 10mm H&R Spacers, Milltek decat downpipes, Milltek Non Res Valved Exhaust, Reyland Motorsports front & rear discs with Hel braided Hoses, full underbody overhauled inc powdercoated subframes and arms, 034 solid subframe bushes and every joint, arm or bush replaced.

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