I have a 97 f250 with 235K. I still have my cat conv on with 3" pipe and no muffler. Has anyone removed their cat conv entirely? Without a muffler would the sound be too loud? I was also thinking about going to 4" pipe. Any thoughts?

 

Pulled mine off and it was not that loud. A bit more but not bothersome.

 

before i had my stacks i had a 3 inch dp with the stock cat that was just gutted, was not much louder then stock

we set up straight 4 inch exhaust in the stock location on my friends '97 its really quiet in the cab

 

I have straight 3" and its not too loud. it sounds a lot better I think

 

I still run my cat with a DiamondEye 3.5" downpipe and 4" exhaust and muffler. I agree with the comments made, but here's something else to think about.

Where I live in Idaho (Canyon County) there has been no smog test requirements. That is changing. I spoke with the Smog ****'s (he was kinda nice about answering my questions) about a cat con on a diesel. He said, "If it came with a one from the factory, it's required by law to be there in order to pass the visual inspection."

So, you might want to keep the cat con handy if you're required to smog check your rig. I wish I ordered the test pipe (cat delete) when I ordered the exhaust system.

 

Nice thing about the diesel's, the only way there going to know is if they pull the build sheet. There is nothing on the rigs (until the 6.0's) that calls for a catalyst...

 

I took mine off and got 1.5 mpg better, and the sound it great but not to loud!

 

i took mine off b4 i got my 4" kit. it is loud at the dp with no exhaust. but take it off and throw it

 

I just emptied mine,sounds fine.not loud at all

 

i got rid of mine