[Runnin'Rich]

I’m thinking about Catted headers for my n52.
I’ve seen a set of s54 headers for sale on FB and considering going through the pain of modifying them to fit n52.

I will need to have the flanges changed to n52 style. Plus I know the runner no. 1 interferes with the AC compressor placement. Maybe I can flatten runner 1 with a hammer or use spacers on the AC compressor mounting to give more room?

What I don’t know is:
1) Will the s54 cats with a lower cel count(I think 200) cause a check engine light with stock tune?
2) will the inner diameter of the runners be too large for a 3.0 as they are designed for a higher revving 3.2? Will I loose some low rev range torque?

I’m hoping to keep emissions systems intact and gain a few hp but more importantly some good sound

Any expert thoughts would be appreciated.

[Ryan1963]

I had the same idea as you, it’s a good one. 200 cell primary cats are stock on the oem s54 manifolds. Delete the secondary cats and youll have the same resistance as going catless on the primaries, like most people do. The goal is to try and remain legal. Someone on the forum has access to flange designs to do the conversion, whether they’ll help you obtain them is another story.

[Runnin'Rich]

I’m just gonna pull a flange from the junk yard. The local yard cuts off the cats with some hydraulic cutters so the flange is left on the engine with some header stubs

[mattanderson]

Cool idea.

Headers seem like the best mod, but I don't want the noise nor emissions concerns.

[desertman123]

R&D is always appreciated, let us know what you find!