Troublesome CEL

[khoov54]

I have P1128 and P1130 on my 1998 Boxster and have read many informative posts on these CEL’s. My investigation indicated the following: leaking oil filer tube, some oil in “J” tube and throttle body. I replaced AOS, “J” tube, oil filler tube, cleaned MAF and throttle body. Posts on this repair/replacement where very helpful, unfortunately I still have those pesky CEL’s. Below I have listed the Freeze Frame data via my Actron ODBII reader on the latest recurrence.

Frame 1 Mod $17

DTC that caused freeze frame P1130

Engine RPM 2897

Load Value 13.3%

Coolant Temp 183 F

Short Term Fuel Trim1 10.9%

Long Term Fuel Trim1 32.0%

Short Term Fuel Trim2 10.9%

Long Term Fuel Trim2 31.2%

Short Term Fuel Trim3 -100.6%

Long Term Fuel Trim3 -100.6%

Short Term Fuel Trim4 -100.6%

Long Term Fuel Trim4 -100.6%

Vehicle Speed 51 MPH

Fuel System 1 CLSD

Fuel System 2 CLSD

I do not have any experience with this data, but it appears the trim 3 and 4 percentages are a problem. I would appreciate any assistance and guidance.

:thankyou:

Regards,

Ken

Georgia, USA

[geoff]

If your MAF has gone bad, cleaning it won't help. You may have to try replacing it. Depending on how many miles you have on the car, it might be time to get a new MAF

[jagman]

Not sure what those codes are for but another problem area on those 986's is the oil separator. If it collapses internally the car will suck air through the filler cap and cause lean codes I think. With the car running try to remove the filler cap. If you can hear air sucking through the cap then the separator is faulty and needs replacement. These things can go bad and not cause any driveability issues until they fail completely and the car burns large amounts of oil and idles rough. Hope this helps.

[khoov]

Not sure what those codes are for but another problem area on those 986's is the oil separator. If it collapses internally the car will suck air through the filler cap and cause lean codes I think. With the car running try to remove the filler cap. If you can hear air sucking through the cap then the separator is faulty and needs replacement. These things can go bad and not cause any driveability issues until they fail completely and the car burns large amounts of oil and idles rough. Hope this helps.

Replaced AOS, there is a vaccum when oil cap is removed. I have not experenced any significant oil usage before or after replacement. :unsure:

Edited March 23, 2009 by khoov

[khoov54]

New MAF corrected the problem Thanks for all your help :renntech: