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Matt, Mechanical Engineer
Category: Audi
Satisfied Customers: 23091
Experience:  BEng hons Mech engineering, in auto industry 22 years
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Audi RS4 b7 saloon Emission control system light on.

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Audi RS4 b7 saloon
Emission control system light on. Diagnostic test identified a fault with the exhaust emission valve, needs to be replaced.Where is the valve is located in the engine bay. Is access gained from underneath near the
exhaust manifold.
What is the cost of a new valve and fitting, my local audi dealer charges £96.00 per hour


Sorry for the extended wait time you've experienced, I've only just come online now and would like to assist you with your question.

the valve is mounted on the inlet manifold and looks like the image

there's a pipe that runs off it and down to the exhaust so you have to undo the mating bolts on the exhaust to remove this pipe too - often this is the problem area as the nuts may be corroded and need grinding / cutting off

a new valve is about £50 and if its trouble free then its a job of about 1.5 hours but if its corroded then this can easily add another hour or so to the job

its a job that can be tackled by any independent so I'd suggest to use this type of garage as you'll have a labour rate of about £50 / hour

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Customer: replied 6 months ago.
Hi Matt
Sorry for the delay in feedback info, partly due to problems with my health condition.The Specialist dealer has not started the repair work on the RS4 exhaust valve, hopefully later this week.Your info on the exhaust valve was very useful, gave me a better idea of labour time-scales and possible problems
that may occur e.g. may need to remove the exhaust. The only issue was regarding the cost of the replacement valve.
Your figure of £50 was not even close, new genuine Audi valve £140.14.The diagnostic test also identified a problem with the clutch switch. I have been told it is linked to the cruise control.
Not recently, when the vehicle was serviced at Audi they identified a static problem, could this be related to the clutch
switch.When the garage eventually carry out the repair work to replace the exhaust valve they will need to suspend the vehicle
on the jacking points, if for example it is left suspended for a long period will is cause any pressure on the suspension,
e.g. DRC / shock absorbers.Kind regards


there's no issue with leaving the car in the air for long periods

this is better than leaving it on its wheels to be honest as cars that are left in long term storage without moving suffer from rusted shocks and distorted tyres