at RPM's above 4500 and at full throttle there is a strong buck and could that possible be the waste gate or the valve in the waste gate staying open, or a turbo sensor and if sensor, which one? Any help that anyone could give would be greatly appreciated. Thanks

 

If you have a strong buck I would think it is not relayed to any kind of turbo control working suddenly. At 4500 rpm's it is where the 2nd turbo comes in and if it over boosts the ecu will shut off fuel to the 2nd rotor. That would be sudden. Does it still happen if you dont go at it full throttle? If so I would look for something spark related.
kevin

 

It only happens in the lower gears when I stand on it, I think it has something to do with the 2nd turbo staying on to long but im not sure, and no it doesnt happen when I dont go at it full throttle.

 

Do you have any mods? What are your boost readings?

 

most bucking will come from missing/loose grounds



good luck,

car 53

 

is the bucking happening in 3rd gear because i have the same problem with mine i also am losing boost when this happens still trying to figure out if u do let me know please it is about 4200-4500 rpm when it does it

 

Need more info, what's your boost pattern?