Headers Question

[nairb2580]

2006 F150 with 4.6L V8. I am entertaining the idea of putting headers on my truck. Is there anything I need to know about before doing this? Will this affect my cats or O2's in any kind of negative way? Long or short headers better? If anyone with a 4.6L that has done this could share your experience that would be great but anyone with knowledge or experience willing to share would be greatly appreciated.

Thanks in advance,
Brian

[COACH_EM_UP]

Definitely long tubes. You will probably take off the catalytic converters once you add the rest of the exhaust and the O2 sensores wont matter. After you put them on, you will need a true tune. Not one of the ones you plug into your cigarette lighter. A true DYNO type tune. Also, depending on what transmission is in that truck, you might have to beef yours up or get a new one to handle the extra HP. Maybe not, but more than likely so. If you are going to do the headers, you might as well do a complete and new exhaust. I dont have experience with the small V8 motors, but I would go with a MagnaFlow. Have them do an X-pipe setup. Depending on your reasoning for the headers might have some influence on what else you do. Personally, I would put a bigger cam in it, change the gears in the rear end, and build the new transmission. That is what I am going to do with my 2007 5.3 liter, but I am looking for more towing power to pull my boat, camper, and cattle trailer more efficiently.

[DirtyDave]

Most will have ports for O2 sensors. If so, it will be fine. Shouldn't have any Check Engine lights.
If you are in a smog county, they may give you grief on your inspection

[WItoTX]

Did it on my '96 Chevy. Probably wouldn't do it again. I snapped the metal pipe (EGR) that runs from the back of the header to the intake when installing the headers, ended up costing another $200 to repair. Then developed leaks where the flanges met up. Never was able to fix them. On top of that, the exhaust bolts going into the engine needed tightening every month, even with high temp locktite. I ended up developing a leak in the gasket because it burned through when I forgot to tighten it that month.

If you go with shorty's they should bolt right in where the factory manifolds sit. It's just a giant PITA, and worse in Fords because they have less room on either side of the motor. With long tubes, you are going to have to cut your existing exhaust to fit, or find a new aftermarket exhaust that bolts up to the long tubes, which I would do since your long tubes will exit with a much larger diameter than the inlet of the factory pipes.

THEN, you still have the cats that will basically stop any flow improvement anyways. Or, be like me, and remove the cats. Then your CEL will be on all the time, but who cares at that point. You could always buy O2 simulators and plug them into your O2 sensors, and it will trick your truck into thinking they are working. My simulators failed after a couple years, and the CEL light turned back on.

[txpitdog]

Don’t go too big on diameter or you will shift the power and torque to a higher than useful RPM range

[hog_down]

What other mods have you done to the truck? There are other options out there to gain HP/TQ that I think are cheaper and less labor intensive than installing headers.

[COACH_EM_UP]

What other mods have you done to the truck? There are other options out there to gain HP/TQ that I think are cheaper and less labor intensive than installing headers.

I am interested in your thoughts. I have heard of a few things, but wondering what you had in mind.

[BigCohiba]

What do you hope to gain by doing this? Long tubes you will generally only pickup power on the top end. If it's a daily driver don't bother. More trouble than it's worth.

[nairb2580]

there are no other mods. I like this truck and hope to keep it a long time as it's in excellent shape so I plan to one day buy an engine and do a rebuild with a cam and beefed up a little as well as have the trans done ore swapped out but that's all in 5 or so yrs. It has 181,000 and I put 20,000 or less a yr so if all goes well should last awhile before needing to do anything. As for the headers, I'd like to increase the hp just a little as the smaller V8 is a little less than what I'm used to (5.9L V8) and also if it helps the sound a little that's always a plus. Mainly for the hp though. It does have a small hesitation from takeoff and while passing if you hit the gas too hard but I don't have that issue usually. Not sure if this would help that in any way but it seems like a tb spacer could help with that issue if it bothers me too much. If putting headers on will require me to beef up the trans and rear end then I will be holding off as I'm not ready for that yet and the truck runs very well as is aside from having a little less power than I'm accustomed to. I don't really pull trailers or haul anything often so it's not a necessity, just a possible want. Thanks for all the input so far!

[BigCohiba]

Based on what you just stated, I wouldn't bother with long tubes. A custom tune would probably gain you more and cost less... If you're looking for better sound, I'd suggest just get a nice cat back exhaust system...

Long tubes will only provide a gain in the higher RPM range. You will actually lose power at lower RPM's.

[KDinTX]

If your set on headers, put shorties on. Long tubes would get you a little more but at higher rpm range than the shorties. Get good gaskets and put some copper seal on them and tighten em up, get them hot and torque them again. Should be good for a long time before needing to be done again. A tune would help as well, but the 4.6 is just kinda gutless in trucks compared to the 5.4.

[ramrod]

In my opinion, you won't need to beef up trans or rear-end for the mear 10-20 hp gain you may realize.

[Scoobyh]

What other mods have you done to the truck? There are other options out there to gain HP/TQ that I think are cheaper and less labor intensive than installing headers.

^^^this. I was going to put headers on my 4.6 mustang, but I didn’t feel like loosing motor mounts and trans mount to get them in, for very little return. I put a off-road x pipe(no cats) and a Magna flow cat back exhaust, cold air intake, and tune. You can turn off the O2 sensors or buy dummies. Underdrive pullies and gears would help too. Don’t worry about the trans, it should easily hold 400-450 hp