I want to make my truck sound like a stinkin truck, but I am not sure which route to take. I am considering taking all 4 cats off and leaving the rest of the exhaust stock until I can get an x pipe and a couple flowmasters. Will that hurt my performance or MPGs. I am already getting 12mpg and my truck is totally stock . If I go this route I am going to need MIL eliminators so I was considering trying the spark plug nonflouler trick. Has anyone tried that out with good results.


Any help would be great, THANKS

 

Removing cats will worsen your gas mileage. It would be helpful if you stated specifications of your truck for one.

Swap your muffler out for an aftermarket one, specifically a Flowmaster muffler, and you will hear it more and everyone else will too.

 

my truck is an '01 5.4l 4x4 off road with an auto trans.

 

Give it a good tune up, look into an intake, and custom tune, and you could see numbers of 15 - 16mpg.

 

Ive got a 04 f150 with the 5.4 and i got sick of waiting to save up enough money to do a full exhaust job, so i cut the old muffler off, went to advanced and bought a si/so super 44 flormaster! The truck sounds great for now, i am very please with the way it sounds till i can get my full exhaust put on.

 

Are you on glue? Removing your cat's will up your mileage. Taking a huge restriction out of your exhaust will make your engine more efficient. Thats like saying headers, a muffler or an air intake are going to decrease your mileage.

It has increased the mileage on every vehicle I have ever done it on.
I have a POS Neon that gained 3 MPG just from removing the cat!

My truck is in the shop getting my cats removed as we speak, more power and better mileage! Just make sure you solder in 1/4 watt 330-1 megaohm resistors in the black wire of your rear O2 sensors to get rid of the code if the ecu hasn't been flashed.

Now as for it being illegal, where i'm at there is no such thing as a smog check. Exhaust shops around remove cats on routine, then sell the cats and get cash for the precious metals inside them.

 

its still illegal to not have cats, even if there is no smog check as far as i know

 

Lets put it this way, in alberta canada they could care less if you remove your cats. Its not illegal and won't be an issue for years to come.

Now in the USA.. some of the laws down there are quite funny.


Sorry DarrenWS6 you must have had a brain fart, I have those on occasion. I was just reading another post of yours heres the quote:

 

true dual straight pipes!!!

 

Well technically what I was meaning by a loss was if there isn't a tune to shut the CEL off, because without mils on various applications vehicles run terrible without cats. I understand and fully agree that more flow more economy, however, it isn't all mechanically true, false readings from a sensor will throw it off pretty good. The cats that I removed were my rear converters, which about 70% blocked sound, and 30% blocked gases. My pre-converters are still in which flow as hi-flows do but still runs healthy and clean without a low end loss, and retaining the economy and increasing it by about .2.

 

200,000+ miles, blown head gasket, full bolt on, no cats, tune was from when I had just my 15749. Pulled to over 4800 in 3rd gear when I let go.

http://videos.streetfire.net/video/f...edo_207005.htm

Also the rear 02's have absolutely NOTHING to do with the way the vehicle runs, they are just there to monitor emissions.

 

Cool video. However I did not state that the rear O2s affect the engine, having no cats without tuning the PCM to stop monitoring them, or doing an O2 mod to shut the readings off, if the computer is getting a false reading there is a chance that performance could suffer because of it. Chance is the word, not definitely.

 

No there is NO chance of it getting a false reading. I was running around for 6 months with the SES light on because I had no cats (p0420) and had no ill effects because of it.

Any code thrown from the rear most oxygen sensors will not effect performance or economy in any way shape or form.

 

ok. thank you for the explanation.