I got a 2003 f250 with the 5.4L and I'm just curious if anyone has seen better mpg by removing the catalytic converter?

Thinking about running no cat with a flowmaster.. any info appreciated thanks!

 

Engine is designed to perform with the converter, without it you're going to have a constant "CEL".

 

It is a $10,000 fine when you get caught.

You can buy a lot of fuel for $10K.

 

Dont know about the constant CEL, though, my 03 does not have a downstream O2 sensor to tell if the cat there or not.

I could possibly see a very moderate MPG increase, but not worth the risks, IMO.

 

I really think that there's nothing to be gained here. I've seen lots of people over the years think that they are improving efficiency through "breathing" mods.

I have never seen it happen. Modern cats are pretty free-flowing and don't do much other than remove air pollutants from the exhaust stream. I wouldn't recommend it at all, there's just nothing to be gained here.

 

[QUOTE=jmiley;11390786]It is a $10,000 fine when you get caught.

You can buy a lot of fuel for $10K.[/QUOTE

Thanks for the information I did not realize the consequences were so severe! And other ppl saying that they have not seen a increase in efficiency is very helpful. That's why I asked, thanks.

 

I agree. Cats do their job and thats it. Theres not much to them. They are generally less restrictive than a muffler.

 

Best mpg I ever got with my truck was in stock form. You will not gain any mpg if your current cat is in good shape and functioning properly.

BTW if you do not have a post cat O2 the truck does not know whether the cat is there or not.

 

You won't get better efficiency w/o a cat unless you have engine control software designed for no cat.

 

I know in NC you don't have to have a cat on a f250 or higher truck but it does hurt your nog by 1 but the performance gain is worth it.

 

Federal Law requires catalytic converters, even on F250's that is why they come from the factory with them.

Federal law prohibits the removal of catalytic converters as well as any other emissions control devices.

 

a few years back in Maine guys were getting caught or not cutting cats of new trucks in the lot, what's in them things anyway? besides exhaust?

 

Platinum...................

 

You most certainly DO have to have them in N.C. to pass inspection.

 

My friend got his CAT stolen when he left HIS WIFE 4-Runner at metro (BART) station. Regardless security cameras and police patrol, the $80 worth of platinum is worth the risk for somebody.
You can buy aftermarket CATs much cheaper than OEM if you need one