how many cats/high flow cat

[lynchy wa]

G'day all, just did the airbox mod (cheers caldwell, you bloody legend) and now onto new muffler (flowmaster original 40) im thinking about getting a high flow cat put on too but dont know how many there are on 2004 v6? can some one let me know and whether they will increase power or lose bottom end torque? im gonna stick with the stock 2 1/4" pipes and bung on a dual 2 1/2" tip. any thoughts appreciated but lets not debate muffler choice, i just like the sound of a 40. cheers

 

[zach84]

how was the air box mod did it make a differance

 

[lynchy wa]

yep less throttle lag, holds well going up hills, 0 - 60 (mph) quicker and better sound (like she wants to not like she has to!) not sure on economy yet ive been lead footing it for the last 20 miles since i did it

 

[CALDWELL]

thanks for the nice words fella made me laugh pretty good...

if i was in your position, personally i would ditch the idea of high flow cats ( money spent Vs. performance gains = minor w/ factory exhaust piping ) ,and put that money into a 2.5'' exhaust, over just replacing the muffler. a muffler yes will give you sound, and slighty increased exhaust flow, but not a whole lot. i can guaruntee that your gonna be wanting more from the exhaust. a 2.5'' cat back set up running the FM 40 of your choice, will give you what your really looking for

now im not sure about what your local emissions laws are like, but there is basically 2 exhaust set ups for the 3rd gen explorer...

1. 2 cats located on either side of the Ypipe, and a resonator shortly after. then the factory muffler. and 2 1/4'' pipe out the back. ( 02-03 )

2. 2 cats located on either side of the Ypipe, with no resonator, then the factory muffler then 2 1/4'' pipe out the back. ( 04-05 )

ive had 2 X's and have experienced both exhaust set ups, my current X was the 2nd option...

also you will feel as though you are losing some lowend TQ, but really your not. what you dont feel in the low end, you really feel 3000 RPM and higher. the change you feel is the Air / Fuel ratio being altered to compensate for the faster flowing exhaust. a tune will correct that...

 

[lynchy wa]

thanks for that caldwell im glad you said that about the hf cats, 4 is a fair old whack to replace. I live in a small town although they like to call it a city 28,000 we only have two exhaust shops the first bloke couldnt get hold of any cat back system to fit an explorer but will fit one i bring in. but the postage for a catback is holy f#$#ing jesus christ on a cross batman expensive. even trying to source my flowmaster is gonna cost same in postage as muffler. Im gonna check second bloke out tomorrow,hopefully he'll bend up a 2.5" pipe from cat to muffler to tip? I think i have a cat in front of my stock muffler (feels like it anyway im a big boy with a crook back bloody hard to check)
sorry resonator in front of my muffler.

 

[CALDWELL]

whats in front of the factory muffler may look like a large CAT, but there is no 02 sensor behind it. which just makes it a resonator, and you can remove. removing the resonator will increase exhaust flow, and allow you to get more power from the exhaust...

even if you dont get the larger 2.5'' pipe, installing the muffler and droping the resonator will slightly improve your MPG / HP...

 

[lynchy wa]

thanks caldwell as always your a wealth of knowledge. what would we do without you.

 

[CALDWELL]

no prob fella

im just a fan of the " intake / exhaust " combo, thats all lol

also something else to look into would be the ( TB Spacer Mod ) reduces the throttle lag greatly

 

[lynchy wa]

got a replacement gasket on order it looks the same but its for an oz ford (im hoping they run the same 65mm throttle body) if it doesnt fit i'll sand down the oem. i couldnt buy the crown or effy gasket here and every ebay shop in the states said that they werent allowed to sell to australia! i could not believe it. also blew out and bought a throttlebody spacer kit and that comes with 2 gaskets, from all accounts they're not worth it.... oh well, at least i'll have some spares if i fubar it (and thats a fairly high probability)

 

[morziac]

whats in front of the factory muffler may look like a large CAT, but there is no 02 sensor behind it. which just makes it a resonator, and you can remove. removing the resonator will increase exhaust flow, and allow you to get more power from the exhaust...

even if you dont get the larger 2.5'' pipe, installing the muffler and droping the resonator will slightly improve your MPG / HP...

that actually is a CAT, sure theres no 02 sensor behind it , but i cut mine open and it has the same honeycomb **** in it as a standard catalytic converter, so its not just a resonator. However, i would still recommend removing it , even more so knowing thats its a cat. I didnt remove my complete unit , but took the uts out , run a pipe straight through , then closed here back up again and put the heat shield back on so it looks factoy.(if the pigs find out u removed a cat u can expect a very large pineapple). definately made a huge difference on my truck.

 

[lynchy wa]

luckily where i am theres no yearly inspections,sniffers or any other way of telling whether youve got 5 cats or 4 (not many pigs around here will lay on their backs on a wet road)no offence to any bacon you all do a grand job out there and just ask any greeny,one less cat is better for nature? yeah. again apologies to all feline owners and pig farmers.

but cheers morziac i appreciate the info,the old guy who i spoke to first was ready to gut me cats but i think removing the 5th is a much more responsible way to go.

their not worried about anything unless its over 85db,will that be a problem with a flowmaster 40 ridgey didge? ps sorry morziac it only took me a couple of hours to realize we're in the same back yard

have you been pulled for that bro, im on an extraordinry is the only reason i ask

pss our backyard is 3x texas

 

[morziac]

lol yeh mate, we got a big backyard alright. So far i havent been pulled up for my exhasut (touch wood) ive been pulled over forbreathos and and been through a couple of booze buses but i just try to idle through or take off nice and slow. The legal limit last i checked here in WA is 89db, but thats taken 1.5 metres from the tailpipe with the vehicle revved to 3 grand then backed off. however i do believe the flowmaster will push u over that limit, most of the commos and falcons that come out with sports exhausts r already over this limit so i wouldnt stress too much mate , as long as ur not drivin like a ******** u should be right

also i think u might be confused with the number of cats, there is 3, one standard size for the left bank, one standard for the right bank and then the larger one as mentioned before after the exhaust join into one.

another thing to think of is if u do decide to gut ur front cats it will throw an engine code cos the 02 sensors behind wont be getting a good reading and u will need to get the sct x3 to turn them off. (i had this isue with mine). there is no sensor issue with removing the 3rd cat though.

just some food for thought buddy

 

[lynchy wa]

gracias amigo.you dont happen to know any shop up there that can do me a y pipe back 2 1/2" exhaust minus muffler do ya?

 

[JoshMcMadMac]

whats in front of the factory muffler may look like a large CAT, but there is no 02 sensor behind it. which just makes it a resonator, and you can remove. removing the resonator will increase exhaust flow, and allow you to get more power from the exhaust...

That IS a catalytic converter! Just because it is after the O2 sensors does not mean it is automatically a resonator.

 

[zerodevil]

it is indeed a cat. ive seen inside the stocker of my old one (after i blew it appart with a 12 gauge). NOW then, it would be a waste of your money in doing high flow cats unless you are planning to go forced induction. I had an aprox bill of 500 bucks to do all 3 of mine, and i had the hook up so i pretty much only got charged for the cats and 20 bucks to cover the use of the torch. If it were me id spend my money instead getting an electric fan, and some underdrive pullies.

 

[lynchy wa]

Thanks to every one ive only just scraped up the cash for the exhaust, then caldwells awesome 2nd stage airbox mod next but jeez forced induction? now there is a mod thread id love to see. to start off find an old 4 stroke lawnmower.....

 

[CALDWELL]

yes i stand corrected...

but its not being monitored, so most just ditch it...

woot 1600 lol