Car is being jumpy from a high roll.
 

Ok so I was traveling up to Dallas last week when I see another s197 and decided to play around. I noticed that when at 65ish, if I drop it into 4th and punch it...the car will go, stop, go. Almost like its cutting out under WOT. Any help would be greatly appreciated.

Duh....your'e redlining it. JK, it beats me.

Nice wandy avatar. Anyone else have any input?

what rpm range were you in? what gears?

Check out the fuel pump TSB. Fairly common plague with the 4.6L where I believe we develop air bubbles in the fuel pump after sustained highway driving. Also, be sure your TCS is off. I've had the same symptoms on a few rare occasions and haven't been able to reproduce it since turning the TCS off but it MAY be just a coincidence.

TCS off?

Traction Control System... Yes, OFF. I only leave mine on during wet/slippery conditions.

I think a little more info is needed.

Was TCS off?

If not , could you have blown off the tires when you made your down shift? If you did could you have spiked the RPM's and hit the rev limiter?

If not, how many miles do you have on the car? What mods? You may need to look at your plugs, or fuel filter. You may also have a issue with the TPS.

Sorry I have more questions then answers.

I have a 06 GT with 22k BUT I've experienced this before on a long highway drive about 6 months or more ago so I doubt it's the plugs or tuning because the first time it happened was before the car was even modded. As for mods now I have a bbk cai with tune/OR X/SLPs. I automatically thought fuel pump when this happened. Would this require me to take it to the dealer to change the pump?