Misfire

JAY MARTIN

MEMBER
2002 PORSCHE BOXSTER
6 CYL
2WD
MANUAL
103,000 MILES

2002 porsche boxster misfire: I had a problem with dirver side catalytic converter. Boxster Raodster. Changed both sensors with universal bosch, driver side. Still problem. Car started misfiring random. Changed catalytic convertor, misfire stopped for about 1 week. Misfire started again only at start up. Fuel Filter not changed yet. Air Filter not chnaged yet. All else changed. What could be the cause?

2 Replies

CWPORSCHE

MECHANIC
58 POSTS

Catalytic converters and oxygen sensors won't cause a misfire in your situation. What cyls are misfiring and how did you determine random misfire?

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Sunday, December 26th, 2010 AT 3:09 AM

JAY MARTIN

MEMBER
2 POSTS

Cylinders 2, 4, and 6 by OBDII readings. I replaced my O2 Sensors first, which I wish I had not done. Then I replaced my catalytic convertor because the filter material had melted from the misfires. However; after much research on AllData and other Tech bulletins, I figured out that the one thing, which causes these symptoms in the Porsche Boxters and other models is the Air-Oil Separator. I changed it at about $106 from AutopartsWerehouse and put it in myself. It took me about 15 minutes. Problem solved. Thanks. Now I'm struggling with the Jaguar X Type Transmission Problem, for which the dealer told me I would need a new transmission. All it takes is resetting the J - Gate. It's a huge differenc ebetween my own free labor and about $10,000 for the Jaguar dealer for a new transmission. As an engineer, I just don't think that's ethical on their part. :)