My Engine Management Light has recently come on, which I had checked straight away. 2 codes came up, one for EGR valve and one for Mass Airflow Sensor. I had the EGR replaced, light reset and 2 days later, the light came back on, this time only for the MAF, so the EGR replacement was obviously needed. the MAF sensor was then changed, for the light to then come back on 2 days later again reading the same fault! The garage were happy to put my old MAF sensor back on as they said it was clearly alright. The car is driving absolutely fine, not juddering, no stalling, no loss of power, good MPG etc which is why i'm confused. I took the car to an Audi specialist who carried out diagnostics and couldn't find a fault, as although the light was on, it was driving fine, so they were also confused. It is a 2011 3.0 TDI that's done 85,000 miles.

Any ideas would be much appreciated! Thanks

Hello Craig,

I would be trying a trusted local diesel specialist rather than an Audi independent. 

Kind regards,

Gareth,

Thanks Gareth, I have booked it in with a Diesel Specialist for next week so will post the outcome once its been in.

Craig

Driving home last night, the car went into limp mode with the orange coil symbol flashing on the dashboard. I took the car straight to have the codes read and this is what came back...

Apparently the DPF is heavily sooted up! Diesel specialist told me they can take the DPF off and thoroughly clean it for £720!!! Is that excessive or is that how much the process costs? 

*UPDATE* After 3 garages failed to diagnose, I decided to investigate myself. I took the air filter casing lid off and removed the air filter and the case it sits in to discover the recently fitted air filter was blocked with polystyrene from the packaging!!! There was also a rubber tube coming out the bottom of the air filter casing which was blocked with dirt. I cleared this and cleared the air filter. I then also sprayed Electrical contact cleaner on the Electrical connection to the mass air flow. I reset the light and have been driving around for a week with no light now. The car instantly felt more responsive! 

Hello Craig,

Many thanks indeed for coming back to us - unfortunately few do, so the thread remains of little use to anyone experiencing similar problems in the future. 

Great news and diagnosis on your part. 

One question I would ask Craig, is do you know the make of the problematic air filter which was fitted to the car? 

Many thanks again and kind regards, 

Gareth.