shooty gti tdi

[geordiesgti]

Ive a 02 gti tdi, the 150 bhp, its been chipped, and recentyly started to blow out soot, it eneraly when used 'carefully'   but after about a week, covers the rear of the car completely, ive had the tested for faults, and nothing came up,   any ideas would be great?  is there a soot filter/ or something that can be blocked/not working/needs replacing?    thanks  andy

[Rhyso]

Possible causes

Faulty MAF sensor
Faulty egr valve
Boost leak


When was it mapped?

[geordiesgti]

it was remapped when I bought the car, and had receipts for a new turbo, its done 156 k, and 30k since I bought it, its putting out about 180 bhp, goes like a rocket, doesn't burn any oil at all,   was fine for over 1 year, and mate wiith a garage has looked at the turbo, and did a full fault diagnostic test with the electronic tester, and found no faults, and ithe soot is much worse when the cars used gently over a week

[Rhyso]

The good old 'computer says can't find anything wrong'   

You have a mechanical issue then. Check the boost pipes for signs of leaks (indicated by oily residue around the connections)

Remove and clean the egr valve and check its operating properly

Unplug the MAF and go for a drive. If it performs worse then its fine; if it drives better then its faulty