Hi guys I have a recently built k20a2, since the rebuild the car lacks power, it crosses over into vtec, but I feel no power gain and its asif the car hits a wall once it reaches 7k rpm. You also get a strange (backfire?) Noise from the engine bay when it reaches 7k. The crossover is audible, once in a while, usually in second gear it will feel like vtec is going to work properly, but feels almost strangled. Car is stock, other than CAI.