CEL P1128 P1130 persistent

[puravidabahia]

Originally Posted by puravidabahia

thanks for the input, i am certain it was bosch on the maf; i am getting ready to just replace the MAF again along with all O2 sensors to see what changes, if anything; the idling is intermittent but usually acts up after being off when at running temp and if not moving out of gear it will sometimes just stall, forcing a restart;

and yes, all stock equipment......i just had a minor service, fuel filter and air filter with no change on the symptoms........higher rpm is fine, only the stopped and/or idling has issues plus only the refuel problem but that is only when refueling when it fails to fire up and causes several restarts after cutting out.....once i force it thru that with 1/4 to 1/2 mile of driving that issue goes away

[78F350]

For the re-start trouble, look into "Evap Purge Valve". It's a valve under the left side intake. Here's an article on the basics (not Porsche, but similar): https://www.samarins.com/glossary/purge-valve.html
It may not be the cause of the P1128/1130, but it is likely still part of the problem.

Here's one discussion here: http://986forum.com/forums/performance-technical-chat/50264-success-finally-fixed-hard-start-while-hot-fueling-issues.html

[puravidabahia]

Originally Posted by 78F350

For the re-start trouble, look into "Evap Purge Valve". It's a valve under the left side intake. Here's an article on the basics (not Porsche, but similar): https://www.samarins.com/glossary/purge-valve.html
It may not be the cause of the P1128/1130, but it is likely still part of the problem.

Here's one discussion here: http://986forum.com/forums/performance-technical-chat/50264-success-finally-fixed-hard-start-while-hot-fueling-issues.html

thanks!.....that "hart start" post sounds like the cure......much appreciated!
i'll update once i've tried that

[Steelepuls]

Have you changed the oil cap? Mine had the same codes and I replaced everything you did. O2, MAF, AOS, plugs, etc. I changed the fuel and oil caps to new and it seemed to fix the problem. Looking at my oil cap and fuel cap, there was small cracks on the o rings. My codes seemed to always come up during traffic and city street conditions. Less on highway going at the speed limit or a little above.

[puravidabahia]

Originally Posted by Steelepuls

Have you changed the oil cap? Mine had the same codes and I replaced everything you did. O2, MAF, AOS, plugs, etc. I changed the fuel and oil caps to new and it seemed to fix the problem. Looking at my oil cap and fuel cap, there was small cracks on the o rings. My codes seemed to always come up during traffic and city street conditions. Less on highway going at the speed limit or a little above.

i had done that but with local auto parts store parts; i just ordered factory replacements today as part of the ongoing troubleshooting......thanks!

[blue62]

With the problems at refill that points to the EVAP system. I would check that system out before replacing anymore sensors or other parts.
There are parts of the EVAP system that are under vacuum while running.
Issues with certain EVAP valves will not show up with a smoke test. So you can have a vacuum leak in the EVAP system that is not detected by a smoke test.
A vacuum leak in the EVAP system can cause your codes and all your other issues.