I have a 1994 ford f150 4.9l.

I replaced the broken exhaust with a direct fit magnaflow catalytic converter and resonator then converted the 2.25 in exhaust into a 4 inch and curved it out pass side after cab. It is extremely loud and bad droning noise in cab. I have looked up a few inserts but don't want to spend the money if I don't know that it will work.

Anyone have good experience or recommendation for a silencing insert for 4 inch exhaust tip that is less then 13 inches long and less then $100?

 

If your running just cats, no mufflers and 2.25 inch pipe then its going to be loud when you dump it right behind the cab. Thats why most true duals go all the way back. Only way to silence it is put a muffler on it or extend the pipes out the back. If you mean the exhaust pipe is 4 inch then thats overkill for any stock motor. Racing motors dont even go over 3 inch. 3inch pipe is plenty. Bigger the pipe louder it will be.

 

Wrong about the cats plus no muffler. Probably the quietest exhaust setup available for the 4.9 using the two factory cats. Factory exhaust pipe cut off after the 2nd cat with 2.25" routed out behind the cab in front of the rear tire is, IMO and many others, the best sounding exhaust for the 4.9. The state inspection stations don't even realize that I have no muffler. Unless I romp on it and create some back pressure pop, it's absolutely unnoticeable. Kind of sounds like a tractor and the sound at speed with the windows down is easily overcome by the radio barely turned up. The 4" exhaust is not good. Like adding a megaphone. Need to stick with 2.25 or 2.5" and that should help quieten it down. I haven't used a high flow cat, but that along with the resonator should be enough to tone it down close to factory flow. If your stock exhaust pipe was still in good condition, it has all of the necessary bends needed to route out in front of the passenger's side tire. I cut my pipe off right after the muffler, pulled it out from under the truck and was able to cut the three or four pieces needed to do the new route from the 2nd cat out.

 

It doesn`t matter how quiet it is, the OP wants it quieter.. Theirs no way to quite it down without adding a muffler or extended the pipes out the rear. Hi flow cats dont do anything to quite an exhaust down. I can put a golfball threw my hi flows. Also I wouldnt go over 2.25 on a strait 6. Its not a HP motor and putting on big exhaust wont help the torque.

 

The OP is asking about quieter than a 4" exhaust setup with high flow cats. As I said, I have no experience with high flow cats. The point that I am making is indisputable, If your running stock cats, and I know he's not, and wants a good sounding, yet quiet exhaust, then then the muffler delete with side exit is the way to go. Myself and others have allot of experience with this setup. I wasn't trying to flame you on your comments, but the fact remains, the mod that I suggested is the quietest, cheapest and IMO the best sounding exhaust mod for the buck. If he does not want to hear the exhaust, and I'm guessing he does or he would have left it alone, then a completely stock muffler and cat setup would have been the way to go. I guess without knowing why he went with a 4" pipe and high flow cats, maybe neither one of us is right.

I see by your profile that your running a 302. If your profile is correct and you have no experience with the 300 exhaust, then maybe you need to search for the 4.9 muffler delete and see just what the opinion is from those of us running the 4.9 with muffler delete. Sorry to be an ***, but there might just be a chance that going back to the 2.25" exhaust pipe run out the side might get the OP where he wants to be sound wise and save him some time and money. That's what we're all here to do is help folks out with all of our experiences.

 

The truck in my sig is just my daily driver. No matter what you cant quiet down an exhaust that has hi flow cats without mufflers. You can run 1 inch exhaust pipe with hi flow cats and it will still be louder than a stock exhaust. OP never said he wants a good sounding exhaust just a quiet one. So if its quiet and sounds like crap then problem solved... Not saying your wrong about the muffler delete on a 4.9 but as I said OP never said a good sounding exhaust just a quiet one.