Is this a tuning issue? Options

[bccentaur3]

I've had my car tuned twice and will get it tuned a 3rd time when I come around to getting the water injection kit. Well since the tune, I'll be cruising like normal and the car jerks. My rpms don't drop or anything, but the car just jerks. Is this caused by the spark plugs at all? Could this be an electrical issue?
O yeah, I get a lot of back fire too. Everytime I down shift and sometimes when I slow down in gear. Now what is this caused by?

[bccentaur3]

Yeah they did. But I have also been told that their wideband is off. To be honest I don't even think Alex tuned my low throttle setting as good as he did the high throttle. Thats why I'm going back one last time.

[presure2]

Yeah they did. But I have also been told that their wideband is off. To be honest I don't even think Alex tuned my low throttle setting as good as he did the high throttle. Thats why I'm going back one last time.

if your just doing WOT throttle dyno runs, they cant tune the lo throttle maps.

IIRC my throttle settings were similar to those you posted (i cant remember the exact %'s) my reasoning is, that anytime your in boost, you dont wanna be on the lo throttle map, which in theory should be alot leaner.
from watching the safc, i could see that at anything over ~25 or so % throttle, i would make boost. so, i set the hi throttle map to ~ 30%, so that anytime i would go into boost, i would be using the hi throttle map, while still being able tune the lo throttle map fairly lean.