Check engine light on 1998 Porsche Boxster

I have a 1998 Porsche Boxter and the check engine light keeps coming on after numerous repairs. The problem that seems to never go away is the rough start. This only happen periodically though! We've replace the fuel pump and several related fuel parts, but the mechanic shop can't find the problem. HELP!

Asked by for the 1998 Porsche Boxster
Check spark plug coils,one could have a short.
2 more answers
if your mechanic is not a PORSCHE specialist, you've taken your car to the wrong shop! sounds like he's thrown
a few parts at the problem as a guess.
Not only does the mechanic work on porsches, the porsche dealer sends him cars!