hey just swapped a us gsr ecu into my hatch to pass emisions and well runs and starts fine but when i enter v tec it feels like its missing or not getting fuel....all hell breaks loose it just goes pop pop pop pop pop and then i let off and drive under v tec. any ideas

 

a friend of mine had this problem once. some jdm ecus dont look for a knock sensor, while the usdm ones may depending on modle and year. if you dont have a knock wired up, that could explain it.

 

Check your codes if the vehicle is throwing a check engine light...

 

or you could just get an ecu off of this guy!. made my gsr come alive! and no check engine lights on. perfect start up, and driveability. not to mention 35 mpg and runs a 13.87 in the 1/4 on 195/50/15 street tires! with open diff lol