Cayenne S with 125K miles just recently stalling when I slow down or at stop with engine at idle. Does not always do this, happened only 4 times in 2 weeks. Drove vehicle 1400 mile trip after first time this happened, and it this only happened once at a stop light during the entire trip. No other issues with engine running or power.
The only other potential issue is a long cranking to start, but his has been the same case since I've owned the cayenne for over 40K miles.

Checked codes with Isoft diagnostic:
-P1023 Fuel high pressure too low during start (I've seen this before months ago)
-P0301, 308, 300 cyl 1, 8, random misfire (I've seen misfire codes before also)
-P0335 Crank position sensor A circuit
-P0456 Evap emission very small leak (I've had this before also)
I can also monitor engine parameters, for example 'Fuel high pressure' seems to run pretty steady at idle around 41,000mb and up to 90,000mb with some revs, 'Fuel high rail pressure' at same time is 40,000 - 73,000. Not fully sure what else to monitor.

My guess from reading posts that I have a crank position sensor going out. Any advise or suggestions appreciated.

 

Cleared codes last night, stalled again driving into work this morning. Only code set today is P0335.

 

Did it end up being the crank shaft position sensor? I’m wondering because my Cayenne started having the same issue at roughly the same mileage.

 

Main fuel pump was culprit. Setting off various codes as aux pumps worked to keep up. It’s possible to read pump pressures with diagnostics.

 

Awesome thank you!