01 S, Multiple CEL's and the rabbit hole - 986 Forum - The Community for Porsche Boxster & Cayman Owners

fishski · 09-06-2019, 04:33 AM

Looking for some technical help please 🙂 01 S with 28k, original owner never had a problem until last month. Have done all my own work, basically maintenance stuff like AOS, water pump, plugs, etc. CEL came on 7/31 put durametric on and codes were P0133 & P1275 both 02 sensor issues, cleared CEL and kept going. All month with steady driving no issues. 9/4 CEL put durametric on and multiple codes, P1130, P1128, P1126, P1133, P0102. Up to this point if the CEL did not come on I would have not know there was a problem as the car ran well. 9/5 CEL came back on with 1126, 1133, 0300, 0304, 0301, 0302, 0306. Did a little research online and it was general opinion to start with easy stuff so I cleaned MAF, TB and air cleaner. Upon startup after doing all this work (cleaning) car ran worse. Rough idle and engine knocking. I did not run the car long. I read after cleaning all the items to disconnect battery for about a minute then turn the key on for a minute, then turn off and let set for 10 seconds before starting. In the meantime I took out my Bentley manual and PP 101. I read the MAF section and I think I fried the MAF because I cleaned the whole sensor including "diode" looking wire on the MAP which seems to be a no, no. I did have another used one on the shelf (same part number .125) so I installed that one, did the battery and key thing again and it seems to run a little better but still rough and still have engine knock. What would have caused what I cleaned to make it worse? Looking for someone to help me wade through the process to track this problem down as I'm going further down the rabbit hole and things are getting worse. I prefer not to throw parts at it but my sense is MAF and an O2 sensor(s) could be bad. Any help would be appreciated. BTW, there is nothing you can say to me that will hurt my feelings, I know for this one I might be a bit over my head but I love learning and I'd love to get back on the road. I have a ton of tools, durametric, etc. Not a professional mechanic but very mechanical.

TrumpyAl · 09-06-2019, 04:36 AM

1. Double-check your work to ensure that there is no unmetered air entering the engine.

2. Disconnect the MAF and see if it runs better.

*Edit* hat off to you for being the original owner.

fishski · 09-06-2019, 04:41 AM

I will sir, I know for sure when I reconnected the plenum I took my fingers and ran it all around the tube to make sure I did not miss anything but I will look again for sure. I will also try to disconnect the MAF and see what happens. In the end, I still have the codes to deal with but I'd like to get it running better so I can drive it to an indy if I really have to. Its more the challenge for me than the $ but I have to figure out when to throw in the towel too.

Lowski · 09-06-2019, 02:59 PM

In chasing my P1128 and P1130 issues I had some similar rough running issues after resetting the codes with the Durametric. On the first startup after clearing the codes the car ran rough and threw a momentary engine knock code. I thought I had a bigger problem than just the original codes.

It turned out I needed to let the car idle for a good 5-10 minutes to let everything recalibrate. To see part of this calibration after clearing the codes with the Durametric, start the car and watch the fuel trim values cycle up and now before they settle in.

Additionally I believe your car has the e-throttle or whatever it is called. There is separate calibration of that I believe whenever the battery is disconnected. My 99 doesn’t have it, so I only have passing knowledge of it.

outsidetheboxster · 09-06-2019, 07:03 PM

Quote:

Originally Posted by Lowski

In chasing my P1128 and P1130 issues I had some similar rough running issues after resetting the codes with the Durametric. On the first startup after clearing the codes the car ran rough and threw a momentary engine knock code. I thought I had a bigger problem than just the original codes.

It turned out I needed to let the car idle for a good 5-10 minutes to let everything recalibrate. To see part of this calibration after clearing the codes with the Durametric, start the car and watch the fuel trim values cycle up and now before they settle in.

Additionally I believe your car has the e-throttle or whatever it is called. There is separate calibration of that I believe whenever the battery is disconnected. My 99 doesn’t have it, so I only have passing knowledge of it.

I might be able to help on the throttle calibration as I just read about that the other day. If you have the electric throttle pedal and the battery has been disconnected you need to turn the key on without starting it, don't touch the pedal, and let it sit for a full minute with the key on. Then shut it off, and then start it. This resets the throttle calibration.

fishski · 09-07-2019, 10:15 AM

Thanks for the help everyone. Problem is fixed. 1/2 my fault, 1/2 bad pre-cat B2 02 sensor. I did not fit the intake/plenum correctly on the bottom of the tube when I reassembled my TB after cleaning. I thought it looked good but it wasn't on 100% and created a vacuum. All is back together and it runs like a top. Thanks again.

Starter986 · 09-07-2019, 01:48 PM

Quote:

Originally Posted by fishski

Thanks for the help everyone. Problem is fixed. 1/2 my fault, 1/2 bad pre-cat B2 02 sensor. I did not fit the intake/plenum correctly on the bottom of the tube when I reassembled my TB after cleaning. I thought it looked good but it wasn't on 100% and created a vacuum. All is back together and it runs like a top. Thanks again.

Awesome! The first time I removed those parts it was a challenge getting that bottom to seat. The next time I removed the parts I sprayed a little lithium to encourage a smooth connection.

Glad to hear you're back on the road. Nothing like a nagging challenge.