Hello, new to the forum, lots of great info.

I have a 99 F150 4.6L 4x4 Ext. Cab.

I'm looking to put new exhaust on it, but have some questions.

Don't want it to loud in the cab, and I leave early in the a.m. for work so don't' want it waking up the neighbors. Also, only want a SI/SO.

Had a Flowmaster Super 44 on a Z71 before, and was to loud in the cab, but nice on the outside.

Is the Magnaflow Race Series Muffler street legal? Would this be to loud? I'm open to anything, let me know what you recommend.

Also, is the stock 2.5" all the way through?

Thanks
TJ

 

stock is 2.5" all the way. and yes you'll be legal. shouldnt be too loud at all with all 4 cats. would love to hear a race series on one of our trucks!

 

Bullet with stock cats!

 

I got MagnaFlow Muffler 14419 Round type.. it is 3" from y-pipe and it sounds great.
Not too loud, but only when you punch it.
My gf says she can hear my truck start, while she's inside her room.
It's decent enough, not too obnoxiously loud, and I definitely get some power from it on 3000 RPM.

Not sure which Magnaflow muffler you are talking about, but
I would choose Magnaflow for my next truck, if i ever do get one.

 

It will be legal, and sounds real good. Just a couple DBs lower than a straight pipe, but having all 4 factory converters will keep it tame.

 

Darren - Which Magnaflow muffler part # do you have on your truck?

And if I decide to remove the 2 back cats, which muffler would you go with then, again not looking to wake up the neighborhood or anything, and would like it to be decent sounding on the inside as well?

Does anyone know the cheapest magnaflow muffler our there, saw 13216 was $46.00 off performancepeddler.com, anyone know if this is a good one or any that are cheaper?

 

I have model #11366 mufflers on my truck.

If you remove the rears, the 11s I have would be alright, or the 14s. Stick with an oval body version if you want to keep it tame, yet loud when you want.

Dont bother with that XL Turbo Magnaflow muffler, they aren't worth buying. Stick with their basic packed and straight through designs.

 

Hopefully, this will be the last question. I would really like to get rid of all 4 cats, as my truck has 150k on it, and would like to remove them as I'm sure they will be a problem in the future.

If I add Magnaflow High Flow Converters to each side, which part # should I go with that would make it the quietest, and which muffler should I go with to quiet it down some more? I know this is an unusual request, as I would like to make it a quiet rumble instead of a roar, don't mind if its loud when I stomp on it, just when starting / idling I need to be quiet.

And if I do the GOTTS O2 Mod, that will make it so my CEL does not come on correct with that setup. Again, I am going to run SISO only. Let me know what you think that would be the quietest setup / least expensive.

I was originally eyeing the 94106 converter, but do they make a longer one that would make it quieter? Would the 94306 be the quietest?

 

Well in that case, 94306 cats with an 18" body Magnaflow muffler. You should be happy with that setup. As long as the shop mounts the O2s after the new cats you should not need to do the Gotts O2 sim at all, but just incase you do receive a light and need to, it will work.

 

Darren - When you say as long as the muffler shop mounts the O2s after the new cats, I was planning on leaving all of the O2s in there orginal mounting positions, and then just cutting the 2 cats out and welding the 94306 in place. Isn't that what you would do? Or does the rear O2 sensor need to be pushed back even further?

I also noticed magnaflow makes a 5in.x11in. Oval (2.5in./2.5in. 24in. long, part# 14260). I am assuming if that will work with the offset it would make it even quieter since its 24" long. Is that True, Is there any difference regarding sound between 5"x11" oval and the 4"x9" oval?

 

Well in that case your plan sounds fine. I thought you were replacing all 4, which then most exhaust installers try to keep it as OEM as possible, if the sensor is mounted in the cat like on LEV emission trucks, and 06+, they may drill a new hole into the new cats and insert the censor, not knowing the sensors need to me mounted after the cats to get an accurate reading.