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Will do sir - was thinking the same, even though the shop said it did nothing when they replaced it, I kinda wished they would have just left it on - thanks for the input.
OK guys - I'm still chasing my problem. I did replace the entire intake with a new one. I removed and inspected the old one and the actuation on the runner valves seemed a bit "sticky" to me, but it did not help. I did run an endoscope down the runners and actually have a video of the valves operating, if anyone was interested to see whats going on inside these things. I also bought an icarscan code reader to continue the pursuit and this is where my next question comes in.... I get the following codes: P0068 "Mass air flow implausible" (limit exceeded), P1074 "Mass airflow partial load implausibly high" (below exceeded) and P0660 "Intake manifold switchover driver" (No signal/communication). From a previous post I stated the MAP sensor was already tried and that was OK. I realize it still could be a bad ground or vacuum switch/leak somewhere...but here's the rub - it runs rough when the code gets thrown, but as soon as I reset the code, it runs perfect again. If something mechanical was bad, how could that be? It's like the code itself is causing the problem - just not sure was causing the code...what's your thoughts? Also, is there a suggestion of another forum or place to ask this question? Would like to get as many thoughts as possible.... Thank you!
Thanks Don! I believe the vacuum control you show could possibly be the issue. I can't however find anywhere any vacuum specs to test it with a Mighty-Vac. If anyone can find something, I'm all ears... I may also call Porsche and see if they can provide something. I also may pull the intake and stick an endoscope down each runner to see these valves look like...maybe one somehow got bent or is obstructed...long shot, but curious now just to see inside, lol. BTW - Search this video on youtube for a good simple explanation of the function of these valves...."Variable Intake Manifolds & Intake Tuning"
Thank you for the reply Don - The valves the mechanic is referring to are in the runners of the intake. There is no "MAF" sensor. I am told MAF is based on the combination of the 3 inputs (ECM, Throttle body & MAP) as mentioned above. The intake itself is the only other element I believe left to replace, which seems to make sense and have any thing to do with this....but I've said that many times already, lol. In addition, after putting a few miles on it after picking it up, it still runs poorly even after the crankcase breather, most noticeably under no/light load - as if the "choke" wasn't working correctly. Very "jerky", falling on it's face then hard acceleration...like a poorly adjusted old carbureted vehicle. Please share your thoughts...about to drop $600 on an intake and take another shot...
Hello All - First post in this group, looking for some suggestions... I picked up a used 2013 Cayenne GTS with an engine light on and running poorly. Took to a Porsche dealer who replaced the throttle body, ECM and high pressure fuel pump, which fixed nothing. I then took it to a well known local German car specialist, who quickly diagnosed it with extremely high crankcase pressure, replaced the crankcase breather, which fixed the running poorly issue. However, it still threw a MAF related code (P1074 and/or P0068). They replaced the MAP sensor, but it didn't fix the issue (so they removed it and didn't charge me for the part, like Porsche!). The puzzle is this - they said the MAF code is thrown based on the combined inputs from the throttle body, ECM and MAP, but as the 2 of those are new, and one (MAP) is confirmed not to be the issue, they don't know what else it could be (all related wiring was checked by both Porsche and local place). I'm still in contact with Porsche mechanic and he suggests it "could" be caused by one or more bad/stuck valves in the intake....makes sense to me, but as I've poured quite a bit into issue already, I thought I would try to get more opinions. What's your thoughts and thanks in advance...this has been much more trying than expected, to say the least. Jim