I have a b18c with 12.5:1 compression. The car had a bucking issue before my tune while I wasn't on the throttle much, just trying to drive a steady lower speed (Just to make sure my description is clear, it feels kinda like you're on the throttle, completely let off and all of a sudden push the pedal back down to where it was really fast and it throws the car forward. Annoying as hell)

Anyway, it went away after the tune but slowly started coming back as it got hotter and now that it's been in the mid to high 90's, the car is to the point that it's also doing it at higher speeds than it normally would like 40 and 60 instead of just 20 mph, and sometimes now it'll do it when you're on the throttle pretty hard.

It stormed today and cooled off to 65* and it didn't do it even once on the way home in the cooler weather (happened about every 20 seconds on the way to work when it was really hot out). I have NGK-7's in right now, I'm trying to figure out if maybe switching to 8's would help (not sure if that's too cold for my comp though) or if anything else would help or if I have to get it re-tuned. Any suggestions are appreciated

 

It sounds like your injector cut off needs to be adjusted.. The weather changing will affect the injector cut off point if the baro sensor is disabled.. What engine management?

 

x2.

Almost definitely a fuel cut issue. You can adjust it yourself without affecting the rest of the tune (assuming this is some sort of engine management program and not just a chip)