I don't know, I think I have too much back pressure, I have a full catback and headers... My friend said I should have high back pressure and the way to reduce it is to tear out catalytic converter, should I do this? BTW I live in FL there are no inspections on vehicle exhausts and emission tests. (unless you are selling to a dealership). also I have a auto and its a 95 sohc vtec f22b1 i believe...