Diagnostic trouble codes

[dpwell]

I have 98 Boxster 5 speed w/ 94k miles. When I first got it (2 years ago 84k) it seemed a little jittery at the higher rpms. Now, for several months, it loses power during hard acceleration around 5000 rpms. Most noticeably in higher gears. It has an mil. I need to get it smogged and it won't pass with a light on. The code is Porsche FC 360&361 / P-code p1128&p1130. These could be above rich or below lean mixture threshold. It seems the problem would be lean as if not enough fuel. I mean it feels that way to me. I believe there is a way to determine this and I intend to study it more tonight. I was going to change the fuel filter. I was thinking that someone who knows what they are doing may recognize the problem and hoping they might help me.

Mike

[Loren]

:welcome:

Please do a search here - P1128 and P1130 have been covered many many times (and it is not likey your fuel filter).

[Chris_in_NH]

the 'cutting out' of power around 4000-5000 frequently is the beginning of a bad Mass Air Flow meter (MAF).

see this thread concerning 1128/1130. scroll down to my post about the easy MAF test and do it. see if that fixes the problem.

http://www.renntech.org/forums/index.php?showtopic=18146

[dpwell]

I cleaned the MAF and it ran much better. So I cleaned it some more and it barely made it back in the garage. I replaced it and it runs better than ever. I have not driven it enough to complete all readiness tests, but I'm sure it is going to be alright. I have other problems with the coolant reservoir. Thank you for your help sending me in the right direction. Mike. :)