Removing a Oem Header for 4th/5th gen prelude

I. Remove original parts.

1. Remove the exhaust manifold cover. It is held in place by three bolts. The AC hosing in the front may be temporarly freed from its mount if there is not enough room to easily reach the third bolt.


2. Remove the original header and A pipe. The layout is 4-2-1 like the Mugen.

A. Loosen the A pipe. Start by appying a penetrant, such as Liquid Wrench, to the bolts. Then, unplug the oxygen sensor wire. Next, lube the hanger (I used Tri-Flow with Teflon).

One by one, loosen the bolts and nuts holding the A pipe to the catalytic converter, the mount and the exhaust manifold. There are eight in all.

B. Remove the A pipe and unscrew the oxygen sensor. Take special care with the oxygen sensor, if you plan on using it later.

C. Remove the heat insulator. Removing the small side heat insulator allows you to access the exhaust manifold self-locking nuts at the end.

D. Remove the exhaust manifold. After removing it, take off the left and right manifold stays, they will not be needed later. Finally, note the orientation of the manifold gasket and remove.

U are now headerless