Make sure you have your spacers installed in the Secondary (downstream) O2 Sensor! You should not get any bucking, jerking or rough idling from a catbypass. I suspect that they installed the spacers in the primary O2 Sensor location, do not drive the car until you verify!!

 

should that take care of the problem ? have you experienced issues with other customers ? i ordered the same system but im getting worried now !

 

Can i assume that you can install a cattless system with headers and as long as the O2 sensors are put back n the car will not require any ECU work?. Just install and go?

 

Yes, I installed my system yesterday. no lights no nothing and the car runs so smooth.