Hey Everyone,

I have a 99 F150 and i replaced both exhaust manifolds and they are leaking again (after 2 years). Im giving up. I have been looking into headers lately and want to buy some that are a direct fit. Preferably shorty headers, so i dont have to modify the exhaust. I also noticed a few days ago that the muffler is leaking, can any of you give me some advice or suggestions on headers you have used and also dual exhaust? And what do you all think of throwing in a cold air intake?

Thanks
Steve

 

Bad tranny mount causing excessive vibrations at the manifold. The stock exhaust damper is right near the tranny mount, when the mount goes bad, all that vibration goes right through the exhaust. Any added stress like that will cause premature leaks at the manifold gasket. I have owned 2 99's and experienced this on both trucks. Until I was told about the tranny mount recently, I couldnt figure it out.

As far as headers, there are a few good brands but you will get better gains from long tubes. Not so much on the shorties, if any at all, just louder. Intake wise, your just as good to save your money and do the gotts intake mod, maybe upgrade your filter. Search "gotts mod" youll see. Lots of people using it with a noticeable difference for the price of about 10 bucks.

 

Way back when, on my brand new 98 F150 4.6L, I installed stainless JBA headers (at the time same a Gibson) and a Gibson single exhaust. I tested the muffler and found it had far better flow with the louvers in a streamlined direction.

Fast forward to last year. I gave the truck to my brother at 225000 miles, with headers still intact, not leaking and sounding great. However, the exhaust was damaged when the domestic niner ran over a fire hydrant. So, I installed the stock ex again. It was a "declawed tiger". I had forgotten how much more power/response the headers/ex provided.

If I had the money, I'd do the same to my 2009 F150 5.4.