my GSR is studdering when i stomp the throttle it just backfires and smoke comes out sometimes, I think maybe im getting a loose connection from the IAT (intake air temp sensor) but i dont know if a sensor could cause it to do that, I checked timing its right on the mark but I do have aftermarket underdrive pulleys is there a different way to set timing with those do i need to advance or anything or what else could be causing my throttle response to be so weak

 

don't assume it's the IAT right away. i don't think i've ever seen one of those go bad anyway.
are there any DTCs aka ecu codes? does the condition happen all the time, or only when the engine is at operating temperature?
if it happens only when warm, i'd check the ECT (engine coolant temp sensor). also check your map sensor reading, and just for kicks... check and make sure all the contacts in your distributor are okay.

 

It did have a code 7 TPS and I replaced that sensor it was doing it alot more before i replaced that but now its down to a minimum backfire and no codes are showing now