I have a 2000 F150 5.4L 4x4. My stock exhaust manifolds are beginning to leak so I'm considering doing headers. Not sure on what brand yet however I do want to do longtubes. However what do I need to do with my cats? I can't remove them because my state requires I have them for emissions. What parts would I need to get this all done and keep it legal? Thanks.

 

I have OBX longtubes with no cats. You can buy them with new cats for like 750 or without cats for 500ish. If you are doing longtubes you will basically need to take all of your existing cats off with the manifolds and replace from there, with the cats provided in the kit. So far I havent had any problems with mine.

I ordered mine from sparktecmotorsports.com (not sure if thats spelled right)

 

If I did shortys could I keep all my stock cats?

 

Yeah but dont expect any power gains.

 

Yeah from what I've been reading the longtubes give you power and the shortys mainly just improve sound. I really want to go with the longtubes, but my state is strict about emissions and idk if I would pass with just the two high flow cats.

 

Im sure if you call sparktecmotorsports and talk to them about emissions and their headers they can give you a definite answer. I had really good customer service when I went through them. Even a simple email will get their attention and they get back to you the next day. Try to get ahold of them and ask.

 

Do you have a sniffer test or visual inspection only? With long tubes and visual you can pass easy. With sniffer you will want a good set of high flows. Long tubes will also require a custom tune to adjust a/f ratios properly and to delete the rear O2s if you don't do the non foulers.