any feedback, results about a flowmaster 40 series original muffler? heard they're supposed to be the loudest, and have a good bit of renosance (or whatever), which i need cause i got a i6, which isnt that loud to start with. and are they street leagal? i would personally run it w/o anything, or a glasspack but i know some of the cops in my area, and i dont have 500 bucks for a fine.

 

i had a 40 series regular on my 97 with a 4.2 six. it sounded pretty good and a lot of people thought i had the 8 cyl. they are street legal in my state, flowmaster says they are 50 atate legal. if you throw on a cat back it wont be nearly loud enough to get pulled over but it should have a great sound to it. i say go for the 40. i just put a super 40 on my new 150 with an 8 cyl. and it sounds great but not as much drone in the cab and its a lot deeper sound, but on that six i think that that reg. 40 will sound good if thats what you want, no huge performance gains however.

 

Go get that 40

 

X2 .

 

alright. thanks, what would happen if i take both cats off and replace em with one high flow magnaflow cat? will any sensors be affected

 

yes they would, my buddy has a 95 with high flows and flowmasters, his check engine light is usually on because of it, but you can find an O2 sensor that sends a false signal to your computer that will eliminate that. im not sure where to find them but if you search the site there should be some info on them. i believe they are called O2 eliminator sensors or something like that. im looking into them as well for my rig, if you find anything let me know. i like your truck by the way, it looks pretty good, real clean.

 

yea, but that wont help fuel economy will it. you need the o2 censors to adjust the fuel intake.. can i get some o2 censors put in the new cats?

 

from my understanding, they are O2 sensors that go where your stock ones would that just send a signal of normal emissions, you can buy regular sensors at a parts store. just check if the high flow has a hole for em.

 

When you install your high flow cats leave in your rear O2 sensors and you wont get a cel.When I installed my high flows,the muffler shop installed new bungs behind the cats to accept the rear sensors.The front sensors are the ones that tell your computer to adjust for emissions,the rear tell the computer that the cats are installed and working.The O2 eliminators can be found on e-bay,they run about $60.00 apiece,buy the electrical ones,not the thread in type.I hope this helped,good luck w/ your exhaust.

 

i didnt see any sensors on the second cat. i wonder if i could just take it off and still be alright as far as sensors go?

 

hey, just crawled under it today, it only has one o2 sensor after the 2-1 cat, then has a line before the second cat running back up towards the engine somewhere. thinking about cutting both off and putting the one magnaflow with an o2 sensor. wadu think?

 

I had a flowmaster super 40 on my '04 4.6L and would not get one again. It sounds great but the DRONE! On the highway and when climbing a hill at a steady rpm it almost gives you a headache. Nice sound outside but LOTS of drone in the cab.

 

I have an I6 with the 40 series!!!

If you decide to get one, you'll have to get a high flow cat too. Cuz your stock dual cats are too restrictive when it comes to loudness. You'll barely be able to hear it on high RPMs which will force you to drive on low RPMs (if standard) which also saves you more gas. Right now it doesn't sound too bad since I went back and got the high flow cat. But when I get my Clifford Headers, It will sound even louder.

BTW, the shop replaced both of my cats with one high flow cat.

 

ok thanks, but where is your o2 sensor and that air pump line at? before or after the hi-flow cat. What brand did you get?