Installing OBX headers, should i keep the CATs

Hello all,

I have an 07 crew cab with the 4.0L. I want to install the OBX short headers and tie then into the pre-cats like the stock manifold. I'm good with fabrication and have my own tig welder so that should not be a problem. are the stock pre-cats very restrictive? I don't even plan on putting a performance exhaust on the truck. I just noticed what a poor manifold design the truck had and know adding short headers would be a huge improvment. I'm not looking for huge power gains but just simply want to correct an obvious fault.

now i will consider upgrading the whole exhaust if it is comparible to the stock exhaust while riding in the cabin. Are the performance gains worth the money?

My real goal is to improve my MPG by making the engine more efficient and add some lower end pickup too. I do a lot of Highway driving.

-Ed

 

Keep the cats and there are a lot threads why you should keep them

 

if it is staying FI, keep the cats

if you plan to boost it, you could do without them. If you take them out you will need an O2 sim to keep the check engine light out.

I have the long tubes, stock y ( cats still there), and the URD catback, and it is plenty loud under load, but pretty quiet cruising.

Justin

 

Good then because that's what i was planning on doing. I'll cut the cats off the stock manifold and tie them into the new headers. OBX has come a long way since their begining.

 

You'd be suprised how good the stock cats flow

 

it not so much a flow issue. some of the hot maps with the APR x1 will melt a stock cat.

Justin