Epc light!

Calzy94

Registered User
Hey guys. Does anyone have an idea why my cars engine management light (epc) is coming on when I go past 100mph? I've got a full Milltek turbo back on it, the light only comes on when I go past 100mph, I loose all boast and it doesn't seem to go any faster even though my foot is hard to the ground. When I switch the car off and on again the light goes off and it works fine, until I go past 100mph again....
 

elpaulio

Registered User
I used to have this in a 2.0 TDi A4 B7 and it was an Overboost fault code, which may make sense with the reduced back pressure from the exhaust?!?

But the only way to tell is to get it scanned for codes either through a dealer/garage/or someone with VCDS as it could be one of a million things throwing the code.

Paul
 

Calzy94

Registered User
I used to have this in a 2.0 TDi A4 B7 and it was an Overboost fault code, which may make sense with the reduced back pressure from the exhaust?!?

But the only way to tell is to get it scanned for codes either through a dealer/garage/or someone with VCDS as it could be one of a million things throwing the code.

Paul
Cheers Paul I'll give it a try!
 

Steph67

Renowned philanthropist and pathological liar
I used to have this in a 2.0 TDi A4 B7 and it was an Overboost fault code, which may make sense with the reduced back pressure from the exhaust?!?

But the only way to tell is to get it scanned for codes either through a dealer/garage/or someone with VCDS as it could be one of a million things throwing the code.

Paul

Sorry, can't help, but would be really grateful if you could keep us updated on the solution as I'm currently looking at a couple of exhaust options. Fingers crossed there's someone here that may have a quick answer.
 

a3_phil

Registered User
Slightly OT, but why, in this age of high res DIS / MMI etc. are we still presented with a single lamp telling us there's a fault?

If the OP had been shown P0722 or something it would be a 30 second job to google it and then be able to contact the dealer or exhaust provider actually knowing what the fault's likely to be...

</rant>
 

Calzy94

Registered User
Sorry, can't help, but would be really grateful if you could keep us updated on the solution as I'm currently looking at a couple of exhaust options. Fingers crossed there's someone here that may have a quick answer.
I got told it's because I've got a turbo back exhaust and it hasn't been remapped to stage 2. The lambur sensor is confused so it's setting the light on
 

davehodgetts

Registered User
Just to add to the confusion... I have a full turbo back cobra exhaust and mine has never came on :) although my engine light has due to the emissions sensor and sports cat.

My EPC light has only ever came on when I unplugged my DTUK tuning box and ran it up the road, but this was before my exhaust.
But as said above an answer would be great :D
 

Filumo

Registered User
I got this too on speeds past 100 -thought it was because I tried to set acc at 120! Car is stock. Light went off after restarting
 

dts439

Registered User
May not be relevant but a long time ago our 944 Turbo had the exact same fault. Would stop boosting (as if hitting a brick wall) at the exact same speed every time. Turned out to be the MAF potentiometer had a poor track at that airflow and caused a duff value to be sensed by the boost computer which reacted accordingly. Fixed by new MAF.
 
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