Recently acquired a 09 cayenne with 115k miles. Very well taken care of and has dealer records since new. Just replaced the passenger side flex pipe with primary cat. Car misfired before but I assumed it was due to the leak from the flex pipe. New pipe is on and it still misses mostly at idle not really noticeable cruising. What do you guys who know this engine well suggest I look for. Current codes are P0300 P0301 P0302 P0303 and p1372. I’ll start swapping plugs and coils around to see if it follows

 

Those misfire codes are all on one bank. Look for either a vacuum leak on that side or check camshaft deviations for bank 1 and bank 2. If bank 1 is reading all zeros your camnposition sensor is dead and needs to be replaced.

 

What is the best way to measure that? I have a generic code reader not sure if it does that

 

Doubt it will do that. Probably need something more Porsche Specific like a Durametric, Foxwell, or similar. I use a Durametric Pro.

A standard code reader.might read a camnposition sensor fault though even if it won't let you see the real deviation values.

A smoke machine would be the best way to check for intake leaks.

 

what’s the best entry point for the smoke nozzle, I do have a snap-on machine

 

Sorry, I wrote my previous answer (now deleted) for a 997, not realizing which forum I was in. You can use anywhere on the intake track where you can get a good seal.

 

Can I tap in on the passenger rear wheel well where the evap pump is? I looked up evap smoke test Porsche 957 and 2 videos came up if you want to see where I’m talking about

 

No, you want to test the air intake side for unmetered air getting into the engine not the fuel system side. If you know how to change your sir filters, yiu can use the hose from the box that leaves the filter housing.

 

I’ll be honest I haven’t even looked under the hood much to know where things are at I just got it, and my other Porsche is a boxster so it’s completely different, my tester comes with cones and caps I’ll mess around with the housing to see where it’s applicable

 

Swapped plugs and coils to the other side of the engine and all codes for misfire went away now im
left with only p1372

 

Also smoke test didn’t find anything, tested each intake pipe both ways

 

Based off using that code in the forum search bar it seems everyone says it’s the valve lift solenoid. Some say it can be removed easily by just removing the valve cover on the passenger side. Has anyone done this on a 957 4.8 S?