Rough idle and rough gear change when engine is hot.

[Gary S K Lee]

Recently my 02 C4S tip. has the stalling at idle problem but now the problem is solved after replacing the crankshaft sensor and the MAF sensor. Now there's a new problem. When i start the car while engine is hot the idle would go up and down between 750-950rpm for about 5 sec and settles at 800rpm which i thought should be normal. After that i don't seem to be getting proper gear changes (for example it won't go from 2nd to 3rd gears at 3000rpm i had to up shift it using tip. button). I really don't know what the problem is hopefully someone here knows what im talking about.

[Loren]

Did you clean the throttle body and buttery when you did the other work?

If not, that should be done.

If the throttle body is clean then you need to read the fault codes for the engine and transmission. Only Durametric, Porsche PST2, and Porsche PIWIS can read pending engine and Porsche transmission codes (reliably) - since many are unique to Porsche.

[Gary S K Lee]

my garage helped me ordered a new MAF and that caused the problem...changed back to old one and works perfectly.

Edited April 21, 2014 by Gary S K Lee