Oh Where to Begin?

[GSpence2]

Boost leak? Vacuum leak? Clogged cats? Any help or suggestions would be appreciated.

 

[Loren]

6 minutes ago, GSpence2 said:

Boost leak? Vacuum leak? Clogged cats? Any help or suggestions would be appreciated.

 

 

Please remind us  - exact model and year...

[GSpence2]

whoopsie! Sorry about that Boss. 2004 Cayenne Turbo, slightly not stock...

[Loren]

Hmm I have....

P2227 Ambient Air Pressure Sensor - Signal Implausible

[GSpence2]

hmm, both sensors failing at the same time? rut ro... ECU crapping out? rodents in the engine harness...  let's have a look

[Loren]

How old is your battery?  4 years or older? If so, I would replace it - Cayenne's do some strange stuff with a weak battery.

[GSpence2]

So I tested the battery today and at rest no ignition I'm getting 12.6 volts. With the engine running I'm getting 13.85 volts. Battery is not even a year old yet. Okay no rodents, ECU check sums are checking out okay, BUT - I'm losing boost, and the timing is being retarded in a big way right when the turbos should start to spool hard about 26-2700 RPMs. Spool up to .3-.4 bar and then le poop! Full dump.

 

Power loss, hesitation, stumble, no CEL - repeat. Hmm...curious...

 

I'll try to capture some live data and post it. I'll try cleaning my MAFs too. I ran some Techron through a couple of weeks ago - didn't really need it but it was a gift so...

[GSpence2]

So I pulled some live data today and am going through it now. One thing I'm not certain about that caught my attention is the correlation of ambient air pressure drop as intake air pressure rises; I thought this would actually be the inverse of what's being reported? Have a look.

[GSpence2]

I realized after the fact some of you may not have a .avi player so I reformatted the data-logging file as a .mp4

 

Edited June 29, 2019 by GSpence2
wrong file

[GSpence2]

So I did some more data-logging today during a portion of my morning commute. Mostly low speed (below 25MPH) stop and go but a couple of places where I could really go fast (30-35MPH). If I am understanding and reading this data correctly my check engine light codes P2227 & P2225 are being caused by a vacuum and/or boost leak? Take a look and pay attention to time slots 12:59 & 16:57. Something weird happens both times when it feels like the timing is all of a sudden thrown off, and the truck hesitates, stumbles, loses power, and then snap crackle pops through the exhaust like a cheap rice rocket with a fart pipe. And each time this is with a steady easy throttle no mashing.