loss of power at 5800 RPMs

[Contr_eras]

Hey everyone quick update, got a Durametric now plugged it in for the first time today. Haven't done any physical work on the car yet but am getting my stock throttle body and plenum shipped down to me, gonna try that before replacing any parts I don't already own. The image below is the codes that came up from the Durametric.

Here is a list of the codes as well.
P0830, Porsche Fault Code 446-Clutch Pedal Encoder (Think this is why my cruise control doesn't work)

p0638, Porsche Fault Code 402-DVE Fault Position Deviation (could this be the reason for my issues? Know BMW calls the ECU something similar to DVE. Would this narrow the issue down to throttle body or fuel pump? Can this be an issue with the tune?)

P0300, Porsche Fault Code 507- Misfire Detection (total)

P0306, Porsche Fault Code 509-Misfire Cylinder 6

P0304, Porsche Fault Code 511-Misfire Cylinder 4

P0305, Porsche Fault Code 513-Misfire Cylinder 5 (think these are all on the passenger side bank (Bank 2))

Also forgot to mention I have a vacuum leak on the drivers side of my plenum(74mm) currently being contained by Gorilla Tape. Car was misfiring like crazy and almost undriveable before the tape job now runs pretty smooth with out noticeable misfires.

[NotthatJake]

Originally Posted by Contr_eras

Hey everyone quick update, got a Durametric now plugged it in for the first time today. Haven't done any physical work on the car yet but am getting my stock throttle body and plenum shipped down to me, gonna try that before replacing any parts I don't already own. The image below is the codes that came up from the Durametric.

Here is a list of the codes as well.
P0830, Porsche Fault Code 446-Clutch Pedal Encoder (Think this is why my cruise control doesn't work)

p0638, Porsche Fault Code 402-DVE Fault Position Deviation (could this be the reason for my issues? Know BMW calls the ECU something similar to DVE. Would this narrow the issue down to throttle body or fuel pump? Can this be an issue with the tune?)

P0300, Porsche Fault Code 507- Misfire Detection (total)

P0306, Porsche Fault Code 509-Misfire Cylinder 6

P0304, Porsche Fault Code 511-Misfire Cylinder 4

P0305, Porsche Fault Code 513-Misfire Cylinder 5 (think these are all on the passenger side bank (Bank 2))

Also forgot to mention I have a vacuum leak on the drivers side of my plenum(74mm) currently being contained by Gorilla Tape. Car was misfiring like crazy and almost undriveable before the tape job now runs pretty smooth with out noticeable misfires.

Hey I have my cats, upgraded muffler, afe air filter, and I still have the stock plenum and original TB. I did try to put on an IPD plenum but the bolt pattern didn’t align so I put it all back to normal minus the few beginning mods.

I am having the same issues as you mentioned. The car starts, I can rev for three seconds and have to let off the gas or the car dies just like you described. You said the problem went away when you put the original TB back on. What do I need to check now because I am at that same point but I am having issues. I don’t have a tune either. Any suggestions?

[Makrilli]

Originally Posted by NotthatJake

Hey I have my cats, upgraded muffler, afe air filter, and I still have the stock plenum and original TB. I did try to put on an IPD plenum but the bolt pattern didn’t align so I put it all back to normal minus the few beginning mods.

I am having the same issues as you mentioned. The car starts, I can rev for three seconds and have to let off the gas or the car dies just like you described. You said the problem went away when you put the original TB back on. What do I need to check now because I am at that same point but I am having issues. I don’t have a tune either. Any suggestions?

Are you having problems only at higher rpms? Does the engine run fine at idle?
Do you have any codes and what are your fuel trims?
Is your AFE filter the oiled or the dry one?
Have you disconnected your battery recently?

Edit: Seems like you have been searching for the part number for the 996 cable throttle body. The part number is 99611006553 in case you haven't found it yet.
I have it on my -99 boxster and have had no problems.

[Contr_eras]

Hey guys old thread I know, I figure I'd throw in what led me to the throttle body. I hooked up the Durametric and had a friend watch all the numbers and info for anything strange/out of the ordinary and saw that the throttle body would just close at 5800rpms exactly. To this day I'm still not sure why it would shut but the stock throttle body fixed it. I still have the 74mm throttle body and might try to run it again someday if I find a good plenum.