98 SC2 Midrange part throttle jerking
 

Having severe driveability issues over 2500 rpms (5spd). Jerking/bucking at partial throttle,full throttle has decreased power (probably timing pull). A little background:

• NO MIL ILLUMINATION or latent DTC
• replaced fuel filter/regulator to eliminate fuel issue
• cleaned egr
• interestingly, with forced MIL illumination (unplug/replug egr) car ran without issue
• replaced egr
• tested TPS (measured 2Ω-~8Ω linearly)

Now I'm stuck. I have no idea where to look next. I'm nearly certain it's a sensor since the car runs fine in closed loop, but I'm not going to keep sourcing sensors and throwing them at the engine hoping I stumble across the problem. Ideas? Thanks.