s2jay again

...would it be harmful to the car to run a header into a testpipe then into an OEM (ap1) exhaust? if so please explain, thanks!

b.r.i.a.n.

no it won't. that's how i had my car for a few months before swapping out the exhaust.

MBHs2k

It won't hurt the car but it kind of negates all the benefits that the header and test pipe can add to your car.

Back S2k

not at all. it will sound better and you will feel a again. i would just keep the tp at 63mm if u dont plan on getting at 70mm exhaust later so there is no bottle neck.

Gernby

The stock header is really good, so the only significant change would be from the test pipe. You would get a few ft-lbs of torque across the whole RPM range, but the big benefits would come from a tune (lowering VTEC engagement).

Breaking Point

Yea it'll be done like they said only benefits from the header( if not paying for high dollar header) while using stock exhaust will be lighter weight.

s2jay again

i see. i have a 70mm dual but im looking to go back to oem. wondering if i can leave the header and tp on. info appreciated tho

s2jay again

plus im using silencers in it so im guessing the oem would sound better than that