If you installed a full exhaust system you really should install the PCV and remap it at the same time. You will notice an instant difference and improvement once your PCV is installed. I wouldn't run without the PCV for an extended time since you are going to be losing performance and potentially running hot.Hi guys, went for a ride on Wednesday, getting lots of popping & backfire on the over run. Checked over flanges & joints yesterday & there doesnt seem to be any leaks, is this normal? I'm going to get PCV fitted at next service in 2000K's, any recommendations on air filters? Thanks.