I have a 1993 F150 with an original flowmaster 40 but its not loud enough for me. I wanna take the cat's off but i've heard different things about doing that. I've heard that it will make the truck run like crap and eat up more gas. Is this true? I would like to take the cat's off and just have the flowmaster 40 on it with a turndown, how would that sound?

 

Would sound much louder. You may have a CEL and maybe a little performance lag. To eliminate the CEL you just need a O2 simulator or two. They are replacement O2 sensors that make the computer think it has cats.

 

What if i just cut off the second cat, would i still have a CEL and some performance lag?

 

You could always replace the 40 with a FM 10 series. Or a small Magnaflow.

 

Well i just got the 40 a few weeks back and like the nice deep tone it gives it but i want it to be louder.

 

You could run a bigger pipe from the cats to the muffler.

 

just straight pipe it

 

If theres no sensor after the back cat then no, but if before, yes. Might not feel any difference cat all on win or loss of performance.

 

The sensor is in the first cat so there would probably be a performance loss right? I guess your wording confused me a bit lol.

 

I'd either leave the cats you have now or cut them off and put in a high flow cat. If you want to do that much work. Or just ditch the muffler. It didn't cost that much and you can resell it and make some of your money back.

 

Without the muffler on its about the same loudness as if i have the flowmaster 40 on it but the flowmaster gives it a deeper better sounding tone.

 

Any cat that has a sensor after it ) as in sensor, cat, sensor ) that cat needs to be there. if its sensor, cat, sensor, cat, that 2nd cat can be removed since there is nothing behind it.

 

Mine goes sensor, cat, cat

 

Ok, that #2 cat should be alright to remove.