no fault codes

[clem750]

My car is showing all the symptoms of a dodgy air flow sensor but when plugged into diagnostics it shows no faults.The car is a 2001 a4 tdi sport with 70000 on the clock.All the pipes seem to be in good condition.
Symptoms are wont go over 60mph unless going down hill
take about 20 seconds to hit 40 mph
cant hear the turbo
drives like a tractor
yet if i nock the engine off and start it up again it drives like it should for about a mile at best.
This has happened suddenly and not over a period of time.

Please any sensible suggestions

[smokey0123]

it sound like the torbo clogged problem to me :(. Try running it without the MAF connected just to eliminate that 1st if you suspect that as they dont leave fault codes unless they are really bad, if it drives better then replace the MAF

[clem750]

nice one,ive unplugged the MAF and if anything it runs slightly worse