2001 4.0, AW4, three catalytic converters, 240,000 km (~150,000 miles).

My exhaust is falling apart and needs to be replaced. I figure while I'm at it I might as well do the whole thing from the cylinder head back including the cats (all three). I'm hoping to get some advice on parts selection/options.

I'd like a good sound but as close to quiet as OEM (dB's) without any drone. This is the family camping machine and we go on multi-day road trips. I don't want something that will be tiresome after the first hour at highway cruise. Highway cruise (~110-115 km/h) with my tire and gearing combo is ~2500 RPM.

We also tow a ~4000 lb camping trailer (Starcraft 11RT fully loaded)

I'm looking to squeeze performance (torque) out of the engine but don't want to go overboard on price. I'd like stainless if it doesn't break the bank. I intend to add some kind of high flow intake and TB in the future, possibly an "RV" cam also.


What do you recommend?

APN header?

Which upstream cat assembly?

The rest of the system? Cat? Diameter?

The system doesn't have to be bolt on but I'd prefer that is was bolt on. I can weld/cut/shape metal no problem but am just tired of doing it.

OT: what's the best online source for an OEM replacement fuel pump?

Thanks!

 

You can piece together a stainless system for under 2k. Any increase in tube diameter quickly decreases torque numbers. Factory 190 hp / 235 torque is about as good as it gets without spending some real serious cash.

 

Also there's very few aftermarket exhaust manifolds for your year because of those extra cats.