wonder what this is?

[audi ben]

just got a new clutch and exhaust sorted but sometimes when i turn the car on the revs go up and drop really low to the point it stalls any ideas??

this is when i turn the key.

 

[Phantom_A4]

Does it do it once you get going and idle at lights/junctions?

My friend had the same problem with the car idling between 700-1000 revs. The problem was a faulty sensor, with the car thinking it was on full lock constantly, draining power from the battery

 

[jcb]

start with a VAGCom check, most likely a MAF issue or temp sensor

 

[audi ben]

ok cheers peeps. it when you turn it on the revs go up and drop to idle but sometimes it drops really low to the point it stalls. only when it is started nothing else its fine driving etc