True duals on 99 f150 4.6 issue

[BEEFKING69]

Hey guys i had 2.5 inch true duals that dump before both rear tires put on my f150 back in august and it sounds really good except its had this pitter patter exhaust leak sound from both side every since. I had all 4 cats removed cause they were almost completely clogged after almost 300 000 miles and it has magna flow mufflers but i cant for the life of me figure out why it has this damn exhaust leak sound.....ive checked and rechecked both sides from manifold to tips and theirs no sign of any leaks????

Now i did notice that the guy used 2 or 2 1/4 inch pipe from the manifold down to where both sides come under the frame.....i didn't catch that after it was done cause the day it was done i was ina rush to get packed for a 900 mile drive to west virgina that night.....could that short section of 2 inch pipe be giving it that leaky sound?

 

[alwaysFlOoReD]

As a moderator I have to point out that having no cats is ILLEGAL. However....
I don't think the 2' pipe would make the sound you're describing. It sounds like more like sticking valves or weak ignition. I've had a similar sound way back when and couldn't figure out the problem. I'm a bit more knowledgeable now and with TRS and google I think I could figure it out.
Good luck,

Richard

 

[adsm08]

Are you 100% sure that the manifolds are not responsible for the leak? The 4.6 and 5.4 are known for warping manifolds.

Look at them closely for popped studs or carbon tracking between the runners. If you find either you have a warped manifold and it will need to be replaced.

Then you need to reinstall cats. I don't care that Florida has no laws concerning vehicles, it is still a federal offense.

 

[BEEFKING69]

The manifolds are good and leak free and i do plan on getting a couple after market high flow cats.

 

[adsm08]

If you can find a big tail-pipe adapter cone you can put compressed air to the exhaust and find the leak that way. Just spray soapy water around the joints until you see bubbles.

 

[BEEFKING69]

Ok bud thx for that ideer i think i can make me one and then ill try that.

 

[adsm08]

Yeah, you will just need a dial regulator to step the pressure down so it doesn't spit the hose back out right away. You can get that piece for about $5 at harbor freight though.

 

[85_Ranger4x4]

It sounds like more like sticking valves or weak ignition.

They tried pulling that crap on me when I put true duals on my 50k mile '02 5.4 when one pipe sounded different than the other. They were all gung ho wanting to tear into the ignition and/or rip the heads off to check it out.

Since it went away when the mufflers rotted out and didn't come back when I put new mufflers on I think it was related to the muffler, as if one wasn't made right or something like that.

It had an extra little offbeat "putt" noise in the right pipe.

Too bad you ripped the cats out, they all but begging for true duals from the factory.