Cat vs No Cat

[Millman]

I just recently had my Cat re-installed in order to have my truck serviced. The question is did you notice a difference with the Cat on or off specifically regarding turbo whistle? I noticed a performance decrease but the whistle remain basically the same.

Oh, I live in CA where smog and vehicle regulation sucks.

 

[RoyBoy]

I have a lot more whistle w/o the cat, even with the stock muffler, put on a walker BTM, THEN you'll have whistle

 

[BamaSixGun]

NO CAT opened up the whistle sound on mine too.

Less restrictive on the air flow too.

 

[MBRPCrazyford]

your power decreased?

 

[Millman]

your power decreased?

I already had the CAT removed and had it reinstalled causing the power decrease. The whistle is still loud and clear as I have 4" pipes off the turbo down.

 

[MBRPCrazyford]

I already had the CAT removed and had it reinstalled causing the power decrease. The whistle is still loud and clear as I have 4" pipes off the turbo down.

oh, ok sorry, got it now.

 

[Zookie400]

high pitched frequencies tend to slp through things like cats and mufflers, so i can see the turbo whistle not changing much, but there must be some difference?

after your service i would definatly kill that kitty again!!!

CT has lovely smog laws closely based on CA's.......but somehow the shady place i got sniffed at forgot to look for my kitty, and passed my truck with a straight pipe, no muffler no cat! when it was on the rollers and being loaded, the walls were shaking in the waiting room, you couldnt hear the TV, all the people walked up to the window to see what the heck was going on. the guy didnt even care, he passed it still!

 

[f100cleveland]

I just received a new economy tune fron Jody at DP tuner and he claimed better mileage with the cat on. I'm trying it now with cat on then if it doesn't improve I'll go straight again.

 

[gunnar]

I'm just about to put an exhaust on my truck and I was told by a Ford diesel tech that I will see some performance w/o the cat but may have more smoke than with. it I don't mind a little smoke when I punch the pedal, but I'm not looking for a smoker. Just wondering what other folks have experienced when they took off thier cat.

 

[atk]

I'm just about to put an exhaust on my truck and I was told by a Ford diesel tech that I will see some performance w/o the cat but may have more smoke than with. it I don't mind a little smoke when I punch the pedal, but I'm not looking for a smoker. Just wondering what other folks have experienced when they took off thier cat.

didn`t really make a difference on my truck. you won`t have a worry about the smoke issue if you decide to loose the cat. it does help a little with turbo spool up and even helped with my mpg(1-2 gain)....hope this helps

just keep it around for when/if you have to have an emission test done.