hello every one, i wonder if you can help, and this only happends sometimes lol as i boost up the engine seems to hesitate and sends really loud cracks through my exhaust this happends at around 0.5 bar, and it just seems to jolt repetitivly untill i take my foot off, and when it runs fine... in 5th gear it hits 1.0 bar and the engine light comes on? decat? relocated air filter? trd leads??? i would appreciate help very much thanx people!!