Very intermittent hesitation and occasional stalls

[RubioBlockhead]

I've had an '04 Cayenne S for a little over a year now. About once a week, immediately upon accelerating (from a stop or on the go), the car hesitates and almost loses power completely. After about a second, it kicks in. On three occasions, it has died. I have not been able to figure out any kind of pattern. It happens when it is hot and cold, going up hill and down, even forward and reverse. I've had it into the dealer where I bought it (CPO) several times, but the story is always the same ... "no faults show on the computer, and it drove fine for us." Any suggestions on how I might be able to pinpoint the problem before the CPO warranty expires?

[jagman1]

I've had an '04 Cayenne S for a little over a year now. About once a week, immediately upon accelerating (from a stop or on the go), the car hesitates and almost loses power completely. After about a second, it kicks in. On three occasions, it has died. I have not been able to figure out any kind of pattern. It happens when it is hot and cold, going up hill and down, even forward and reverse. I've had it into the dealer where I bought it (CPO) several times, but the story is always the same ... "no faults show on the computer, and it drove fine for us." Any suggestions on how I might be able to pinpoint the problem before the CPO warranty expires?

Try this:

In a parking lot, or some other safe place try to accelerate with one foot on the brake (very lightly) and the other pushing on the gas. The engine will cut power as it thinks you're pushing both pedals at the same time.

Does that feel at all similar to what you've been experiencing?

If so, there was a software update that increased the duration that both pedals would need to be depressed before engine power was cut.

[mudman2]

what you describe is very close to what all 04 S's mine included had from new, i thought all were sorted out by now. The DME unit had messed up software and multiple tries to fix it were made in the early days, some had multiple DME control units replaced. Some had transmission control units swapped. because its a software/firmware issue PIWIS will see no fault codes. I would get them to verify all the control units match in version numbers

[wvicary]

Have the fuel pumps checked for pressure and volume output. What's the milage on the unit?