RS4 Saloon 2006 Emission Control System Fault

[Bobfin]

Still no car back yet, called Audi today awaiting authorisation for additional works from Audi UK, not quite sure what's happening, told it should be done by tomorrow, Thursday.

[Bobfin]

After Glasgow Audi having the car for 10 days, replaced 7no. coil packs and part of the wiring loom that they told me was also requiring to be replaced due to the issue with the coil packs i now have the car back. Apparently the delay was because Audi UK wanted 2 written reports and images to back up what works were required, took a while but all running well now, with no charge, my only complaint was the time it had taken, although they did give me a new A4 courtesy car for the duration.

[sync24]

Hi there, looking for some advice, was driving my car today and the emission control system light came on - car felt slightly rough and not as smooth as usual

First of all - holy thread resurrection!

My emission warning light came on today [yellow engine icon] - oddly enough just after my fuel light came on - a full tank of Momentum 99 later and the light is still on, it didn't flash, it just came on and stayed there. I've only done 200 miles and had the car a week - FFS just one of those things. The car does seem to be running OK and I can't for sure say it feels any different and certainly does not feel lumpy or misfiring.

Fortunately, I don't need the car next week as I am away skiing - my ever so helpful father in law is going to take it to my local stealer [who have looked after me before] - Guess it's gonna be coilpack related [if it's not a false alert]. Would they change all of them at the same time or just one [if it's that] - can anyone else comment on costs involved and can I drive it tomorrow so I can get my train to work or is it best not to? Finally - I know that their was some recalls on coil packs but I checked the car before I bought it and none where outstanding - any thoughts on this?

Kev.

[MikeFish]

The recall was for earlier cars. As yours is an 07 it probably wasn't eligible (I assume they came with the newer type from factory). The coils cost about 20 or 30 pounds from memory and fairly easy to change so can't imagine labour will be much (I changed mine myself in about 30 mins or less). They will only change the faulty one (assuming that's what the problem is). Do you have a Vag Com cable? Hat will tell you what is throwing up e fault light.

[sync24]

The fault code is P0491 - Secondary Air System Bank 1 - The breakdown guys turned the light off and suggested I get it into Audi for diags. So it's probably not the coil pack.

[MikeFish]

I think coil pack normally shows as a cylinder misfire on the computer.

[adsgreen]

The fault code is P0491 - Secondary Air System Bank 1 - The breakdown guys turned the light off and suggested I get it into Audi for diags. So it's probably not the coil pack.

Vac leak or sec air pump fail.

[MikeFish]

Copied from another site so I don't know how accurate it is:
"PO491 or 16875 is a Secondary Air System fault Bank 1. Bank 1 refers to the passenger side off the engine. The combination valve for secondary air injection did not preform as it should & set a fault. The valve is located under the plastic engine cover at the rear of the right cylinder haed. There is a plastic tube from the air pump to the valve that breaks, the valve sometimes fails, there is a vaccum hose that opens the valve that also sometimes fails & rarely the Air Injection Vacuum Control Solenoid Valve fails. The plastic tube unpluggged/cracked or failed valve are the 2 most comon failures I see. Beond that there isn't much you can test using a generic scantool. If you have a factory VW/Audi or VAG-COM scantool I can give you more help. Good luck UPDATE>>>> If it's a vac leak it's in the small hose from the solenoid valve to the combination valve. The super charger may affect the vaccum, but I would exspect to see more codes if it was really messing with things.. The air injection system only runs for about 1.5 minutes on cold starts. If the plastic tube is broken you will hear what sound like a small exhaust leak. What mods have you done to this thing. You may want to invest in a VAG-COM if you are tuning it yourself. It's pretty cheap. http://www.ross-tech.com/ It makes dealing with VW/Audis much easier. You have a generic code reeader of some sort, but I'm sure there are other codes stored that won't show up with out VAG scan capabilities.

Obviously you don't have a supercharger but the majority of it is probably still valid.

Oh, and I think it was an american site so where it says passenger side that will be your drivers side. I think I had my secondary air system removed when I had my pre-catts gutted and cold air feed fitted and therefore this code would have been maped out.

[sync24]

Thanks Mike - appreciated.

['R'e'S'pect_4]

thread with info.....

http://forum.rs246.com/viewtopic.php?f= ... L&start=30

[E3ddw]

I had the same problem. Went to glasgow Audi and I was shocked at the service. Guy came out and asked if my car was an A4 TDI. My jaw just dropped at how disgraced I was. He then later told me I would have been charged for a courtesy car. So I just told him to leave it and I'll never be at glasgow Audi again.

[sync24]

It's booked in with my local dealer - East Kent Audi - On Monday next week - they have been great to me in the past - let's hope they continue to provide a good service.
£115 just for plugging it in though

Will report back

[sync24]

Well .... Nothing to report on the engine emissions problem - Audi confirmed "no fault" and cleared errors - BUT (there is always a but) they identified the brake fluid was due to be replaced so I had this done and also both front shocks are showing fluid "weaping" so it looks like I have been a victim of DRC! I'll take time to go and visit the service manager to discuss if they will change on a good will basis as the shocks are coming in at £1100 without labour. If they won't swap I'll may bite the built and go for the KW coil overs.

Is this a viable option or should I stay OEM? Is the KW really worth the upgrade?

Cheers - Kev

[MikeFish]

I had the same problem. Went to glasgow Audi and I was shocked at the service. Guy came out and asked if my car was an A4 TDI. My jaw just dropped at how disgraced I was. He then later told me I would have been charged for a courtesy car. So I just told him to leave it and I'll never be at glasgow Audi again.

LOL, when I took my car for an MOT last year, the mechanic went out, took a walk around my car then came in and said 'it's a diesel isnt it?'. WTF!


Sorry can't help with the coilover query as i am still on standard suspension. Sonny is going back to SS+ and DRC soon though. From what I gather coilovers are better for tracking but with the state of the britsh road, if you don;t spend much time on a track, then you might be better of keeping the DRC. But this is just from what I've read, havent tried it.

[E3ddw]

Well my mechanic just sent me a pic of what arrived at his unit. Will have these fitted tomorrow.
I haven't suffered any DRC poblems yet on my SS suspension.