Emission control system warning light

[kaisersolsay]

Hello,

Only had my B6 S4 for a few days now (2004 21k on the clock) and the emission warning light went on today? I was totting along doing 55mph for around 15 miles (to see what mpg I'd get) and noticed the light had come on. Its orange, not red.

Is it safe to keep driving this weekend? What causing this? I heard that it means that the fueling is lean.

Anyone help?

[BlingBling]

I was totting along doing 55mph for around 15 miles (to see what mpg I'd get) and noticed the light had come on. Its orange, not red.

I think it was the cars eay of telling you to stop driving like Miss Daisy and to unleash to roar of the V8.

Other than that I have never had that problem, emissions light that is.

[kaisersolsay]

ha ha very good.

Seriously...anyone got any info? Gave her a good thrashing last night, but light still on.

[BlingBling]

Is your car standard? I have heard of S4's with sports exhausts having emission problems. Other than that it looks like a trip to an indie or the stealers.

[kaisersolsay]

Completely standard. Took her to the stealers today and they checked for fault codes. Was told that an electrical fault was indicated but could not find anything wrong so reset the light. Have driven her 30 miles and light still off. If it comes on again I am to take her back in for investigation. Wait and see i guess.

[tuscy]

We had this problem on my wife's A2 after I borrowed it for a day, the light came on when I floored the throttle with a cold engine, this over-fuels the engine and puts slightly more unburnt fuel into the exhaust system where it's picked up by the emissions sensor.

The ECU on the A2 resets this fault after a few days (or engine starts), probably the same on the S4. Has is gone yet?

Mind you if I had the same fault on my S4 I'd be getting it checked straight away, don't want to bugger up 2x expensive cats! .... although it would be the perfect excuse for a Miltek system.

[kaisersolsay]

The dealership reset the light, and 2 days on its still off.

On a separate point; I noticed that most filling stations offer only 97RON Super Unleaded, when the owners manual says the can should be run on 98RON for full performance. Anyone know which stations sell the 98RON?

[kaisersolsay]

Light came on again guys. Took her to the stealers again and they told me they had to replace the lambda sensor. Now seem to be getting better MPG....Crieff to Cupar....35 mile trip....sat at 60mph and got 30.2pmg ave!!! Running her on 95RON unleaded.

[smcmilla]

I had the same problem on my S4 (B6 Cab). I only had about 23K on the clock at the time. One of the cylinders was clogged with oil and this was causing the problem. You could really tell the difference when trying to pull away, it really sounded and felt odd.

Anyway, it was consuming far to much oil and this was leading to the clogging of the cylinder. After a very drawn out affair and testing of oil usage, they finally opened it up and found a build up inside a couple of the cylinders. At the end of the day they replaced the engine.

It is now running like a dream and I have not had to top up the oil for 1K miles (unheard of before this started). All under warranty so very happy.

[kaisersolsay]

It came on again a the other week. Took her to the stealers and it turned out to be the lambda sensor, which they replaced. All sorted now....looking forward to speed Sunday at Knockhill!! My mates taking on his '54 plate M3, so should be fun. Going to rig up the camera so will upload some footage on Sunday night.