Anyone running a high flow cat on a 4.0?

Torn66 · 10-29-2002, 03:32 PM

i am installing a Pacesetter header w/ a rustys exaust system- on my 97 4.0... I already have a k&N cone filter.

I have a high flow cat i could install as well- doing the whole thing from the header back. I read in another thread I may actually loose low end with this set-up (w/ the high flow cat)...is that true?

would you guys reccomend installing the high flow cat or not?-

either way i have to put in the header and the muffler to replace busted/cracked parts.

any help would be great- !!!

KnightFire · 10-30-2002, 07:01 AM

Your always better off trying to reduce the amount of constriction in an exhaust, as long as your not going totally crazy and putting in a 6" system, LOL.

If I had some extra money left over I would have done this very thing, but I have a Borla header/Cat-Back exhaust system and their were fairly expensive.

KnightFire

hjeepxj · 10-30-2002, 06:12 PM

i have dynomaxs 53.00 cat, it is a good highflow cat

id reccomend it

youll be running 20 extra hp with all that, 25 with the cone! 215 all together, at the crank! its almost time for either an iat sensor relocation or fms #24 injectors

Torn66 · 10-31-2002, 06:54 AM

hjeepxj- why would i need new injectors?- just to get more fuel - would i be ok with this setup and no other mods?

KnightFire · 10-31-2002, 08:00 AM

Getting new injectors just because you have a few bolt-ons is rediculous....don't waste your money.

I can garantee you that you are no where near putting your OEM injectors in static mode 80% or more of the time. This is the rule of thumb to knowing you need new injectors.

I do agree with the IAT relocation, put it where your air filter is housed or just put a 4.7kOhm resistor in it...does the same thing, tricks the PCM into believing its 56F...which of course makes you run a bit rich. Ya might pick up 1-5 HP with this trick.

KnightFire

Torn66 · 10-31-2002, 08:05 AM

i've heard of that- it just advances the timing right?...i have seen resistors for sale on e-bay- but have heard they can hurt the engine. I know if im driving a few hrs in 80 degree heat and my timing is that advanced...it canmt be good- what do u guys think?

KnightFire · 10-31-2002, 01:42 PM

I used one on my Formula for YEARS in all kinds of driving/weather conditions. Did not harm a single thing.

Just go to radio shack and get the resistors, it will cost you .49 for a pack of 5.

Here is a neat site (that sells their own product) but it pretty sums up what the IAT resistor trick does.

http://www.speedtweaks.net/IAT_Adjuster.htm

KnightFire