sfurner

About a month ago I started working on my exhaust system 40 series flow masters and O2 sensor delete plugs. Ok, before I cut the converters off, I asked people if the 4.6 required any amount of back pressure. After some conversations on this subject I came to the conclusion that most of the people that have done this saw an increase in horse power, gas mileage and stated that the sound was not unbearable. A friend of mine owns an exhaust shop and has been working on exhaust's for around 20 years and said he has done this several times with good results also. OK, my car is so unbearably loud that you cannot hear yourself think. And when I get pulled over, cause its going to happen I hope I see the Cop cause I am not going to be able to hear him. Gas mileage is horrible and I know for sure this engine needs more back pressure because it runs like ****. SO I ^$#@ up! NOW WHAT! GO AHEAD AND REAM MY $#@.

Can I go with a more restricted muffler? Don't say weld your cats back on....please.

If anyone has ran into, or knows someone that this has happend to, please respond?

Thanks
SFurner

JonBeast

Get an aftermarket o/r midpipe....or a high flow catted one. Cutting off your cats is ghetto.

StickShifty

since you cut out your cats your kinda in a jam. you can put on your stock cat back, get a not as loud catback, still gunna be really loud. ALso you can weld in the cats, or buy a new catted midpipe since you hack up the stock one. if i were you i would weld in only two of the cats, cheapest thing to do, or put the stock catback on and sell the 40's. but buying a new mid pipe is going to be really expensive.

new edge or sn-95???

Dan04COBRA

If you feel as though you lost hp, it sounds like you removed the cats and didn't do anything to solve the check engine light that you most likely have or is on it's way, which would explain the crappy driving experience you are having right now.

You should have never done it the cheap way.

Spend the 200 or 300 bucks for a catted mid-pipe.

MustangMafia

Theres a $200 catted midpipe?

Dan04COBRA

I got a catted pypes x-pipe off ebay for uhh. $240?

sfurner

Money was not the factor here. I ran 3" stainless to the 40 series mufflers to try and unrestrict it. Which have done many times before on the the old 5.0's. I am just experimenting here. I bought this 99 to do just that. I have a 04 GT Convertible that I just put 40 series mufflers and u can hardly hear it. Ghetto? Who is this guy? I wouldn't think of criticizing someone asking for help or input. You other two guys, I apprecitate your input. I dont have a check engine light. Lets hope it doesn't come on. I used the delete plug.

Tomorrow I am going to put dynomax muffler's with three chambers if that does not work I will start welding cats in?

SFurner

gt96stang

Run a 2.5" pipe instead of those monster 3 inch pipes. That right there is your reason. You are right, you are not getting enough backpressure. Usually aftermarket catbacks are all 2.5" pipes.

hurleymasta

i got an idea!!
you said you bought delete plugs right!?! i believe on the computers it still needs the 2 back o2's to "work right" i think i would screw some o2's back in and then buy some MIL eliminators, that will take care of the computer and tell the computer you still have cats...hahahah stupid computer, we finally outsmarted you!!! or put the cats back on that will make it sound quieter and you wont lose much power
tried on the input,
Ryan

Dan04COBRA

The delete plugs will do nothing to help and 'hoping' it won't come on will only let you down in the end. The light will absolutely come on and you will absolutely have a loss in performance. Just spend a couple bucks and buy the MIL's.

If money isn't an issue, I see no reason as to why you are trying to save a penny and end up just making your car slower than it already is.

If your 40 series are quiet, then you don't have true original 40 series Flowmasters.