Header/Downpipe questions

0

00BlackClassic

NAXJA Forum User

Location

Lubbock

• Sep 7, 2014

• #1

I have a federal emission 2000 xj. It doesn't have the 2 cats on the downpipe. I'm thinking about doing a header as I have a cracked manifold and I came down on my exhaust when wheeling one time so its a bit tweaked. Main question: is there any reason that I couldn't switch to a 99 and down header if I just changed the downpipe? There's many more options for 99 and down and I can't see a reason why you couldn't just get the header, and the downpipe as everything else seems the same after the downpipe.

 

Johnnie Walker

Piece of Fish!

NAXJA Member

Location

WA state

• Sep 7, 2014

• #2

Does it still have the 2-piece short manifolds?
In theory, yes, you can swap 99-down exhaust. However depending on emissions/testing where you are, the aftermarket headers will not technically be legal on your vehicle.
But yes, header with matching downpipe will be plug n pray.

 

0

00BlackClassic

NAXJA Forum User

Location

Lubbock

• Sep 7, 2014

• #3

Yeah the two piece manifolds. And I'm in lubbock they don't emissions here.

 

Johnnie Walker

Piece of Fish!

NAXJA Member

Location

WA state

• Sep 8, 2014

• #4

Then yes, a pre-99 manifold/header and matching downpipe will work.

 

Talyn

NAXJA Forum User

Location

Radford, Communistwealth of Virginia

• Sep 8, 2014

• #5

Yes, an earlier header will work on the federal emissions 00+ 0331 head. With some exhaust work though.

As for later headers you still have plenty of options: Thorley, OBX, AFE, Borla, JBA, and Banks.

 

0

00BlackClassic

NAXJA Forum User

Location

Lubbock

• Sep 8, 2014

• #6

Well besides changing the downpipe it should be the same after that right? I'm going to replace all of it anyway. I have exhaust leaks all over the place.

 

Talyn

NAXJA Forum User

Location

Radford, Communistwealth of Virginia

• Sep 8, 2014

• #7

Yes. Just make sure you have the O2 sensors where they need to be.

 

B

bigdaddyjlove

NAXJA Forum User

Location

Atalanta

• Sep 8, 2014

• #8

The Non pre cat 2000 model only has one upstream sensor and one downstream.

The upstream is in the crossover pipe right by the bell housing on the drivers side.

The bungs for the two upstream sensors on the precat model are in the manifold, but are plugged.

Switching to an aftermarket header is pretty simple.

 

0

00BlackClassic

NAXJA Forum User

Location

Lubbock

• Sep 9, 2014

• #9

Cool thats exactly what I needed to know thanks guys.