Rep!

[C5 2000]

Set the Accel Thresh table to 0.

[ttz06vette]

You know that porting changes the relationship between throttle angle and available flow area (actually % of max area), right? There are tables in the background of the ECU that describe this relationship that we do not see in HPT, so you are left with a mismatch. Adding boost to the mix only makes the flow differences more pronounced, and practically begs for a mismatch between predicted and actual flow that leads to REP.

This eventually happened to me with my LPE ported TB.
Was o.k. for awhile but eventually began throwing codes and going into limp mode every time I got on it in boost. Tried everything and eventually found it to be the mounting location of my meth nozzle. I had it mounted in the 3 o'clock position on the coupler before the TB. By rotating it to the 6'o'clock position all codes stopped and car ran fine.

[5_Liter_Eater]

Set the Accel Thresh table to 0.

I don't see that table/field anywhere.

[5_Liter_Eater]

This eventually happened to me with my LPE ported TB.
Was o.k. for awhile but eventually began throwing codes and going into limp mode every time I got on it in boost. Tried everything and eventually found it to be the mounting location of my meth nozzle. I had it mounted in the 3 o'clock position on the coupler before the TB. By rotating it to the 6'o'clock position all codes stopped and car ran fine.

Interesting. My meth nozzles are pretty far upstream though. I can't see rotating the nozzles making a difference in my case.

[ttz06vette]

Interesting. My meth nozzles are pretty far upstream though. I can't see rotating the nozzles making a difference in my case.

Mine was right up against the TB housing. I squeezed it in the coupler in a small gap between the MAF and TB. Didn't want to cut my intercooler shroud. Not sure if there was physical contact with the butterfly or if it just didn't like where the spray was occurring, but either way it doesn't sound like its your problem.

[C5 2000]

Fuel Cutoff,DFCO Acceleration Based.

[c.u]

Bill is there any other codes? Have you checked that the throttle blade has good spring pressure and there is no binding. Have you checked for poor connections at the tb and the ecm. Have you loged any of the aclelerator 1 and 2(%) and etc pedal 1 and 2(v).

[5_Liter_Eater]

No I haven't done any of that. I did find a thread about the P1516 being caused by a loose wire to the TAC and I checked that over breifly. I'm pretty much being like Ned Flanders' beatnick parents here; "You gotta help us doc. We've tried nothin' and we're all out of ideas".

[DSteck]

Put another throttle body on and see if it still does it.

[5_Liter_Eater]

Also a good idea.

[DrLoch]

No I haven't done any of that. "You gotta help us doc. We've tried nothin' and we're all out of ideas".

Best response yet.....

[68Camaro]

did you ever get this sorted?

I'm having this problem with a 2007 z06 with a turbo on it....

[03Sierraslt]

Bump for updates