mine happens to have 4 so it can become a lot of money I need my truck to go to dr visits can't afford to replace them and they are bad .....what should I do in this case. ...01 f150 super crew cab .....

 

Call your congressman.

 

altering catalytic converters are so 1976..

they used to make "TEST" pipes to see if cat is bad..
remove cat., install "test" pipe.. and drive and see if cat was bad.. that also was 1976...

 

here in ca any tampering of the cat is illegal,any cutting/welding around the cat will if inspected fail the test,also 30+ years ago got caught speeding,cop looked under the car,got ticket for glass packs and no cats,the fine for the cats being removed i paid on that for a year,not good,

 

The one thing I will say about the cat is it does change the tone of the exhaust. It is a expansion chamber and it will smooth out the pulses from the engine.
I ran my truck straight piped in 4" from the turbo back. Truck was raspy at wot and had cab drone around highway speeds.
I knocked out the cat and welded 4" pipe to both ends. The exhaust sounds much better with the empty cat body in the exhaust. Strange as that may sound it's true.

I also saw lower EGT's around 100* with the cat knocked out. I can't say it lowered or gained the HP. But it absolutely sounds better.

 

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So I guess I really needed those 2 piece spark plugs that Ford installed in my motor......

 

Yes, the engineers at Ford are very smart and never do anything stupid! My 2004 F150 with 5.4 Triton is proof of that - two piece spark plugs & all. Or maybe they were just trying to sell parts because they're upset that cars last longer than 100k these days...

 

Personally...if my car came with a cat it stays on until such time when it breaks then I replace it with another cat, like o did on my wife’s suv. cost me $1200 to buy the new cats. The big issue was these cats were integrated in the exhaust manifolds. Either way I don’t wanna deal with trying to fool the computer in thinking the cats are there, and going through all the bs only to have to figure out how to illegally pass the smog test. Who really has time to screw around like that. I want a car that runs well and doesn’t give me problems.

 

I know this posting is an old one BUT; I Had to laugh When I saw this one…. I mean, when I used to live in “Taxachusetts”, not a day went by when I didn’t see at least one article in the newspaper about a cop with x-ray vision busting a driver/car owner and throwing them in jail for gutting their catalytic converter….🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣

I mean once in a blue moon if someone had a loud exhaust (like open headers) or a loud audio system and pissed a cop off they might get a ticket or POSSIBLY thrown in jail (after pissing the cop off some more)…..

BUT even though most people end up creating leaks and more harm than good, as long as you don’t have to worry about passing emissions test (and sometimes even if you do), gutting your converters or converter is a good option if performance exhaust parts are not available for your vehicle…..

Oh yeah… Be sure to either restrict the flow allowed to enter the rear O2 sensors (catalyst monitor sensor) or use resistors/emulators to send the correct voltage to your engine computer so that it “looks” like the catalyst is present and functioning…. The easiest way is to take copper piping and cut a piece to cover the end of the sensor and then install it back into the converter…. The only other recommendations I have are to Make sure there are no leaks and don’t use any universal pipes or a bunch of adapters to accomplish ANYTHING… you don’t want any leaks….

Knowing what people do their exhaust I probably shouldn’t have said any of this but if done correctly you CAN turn your 4.0 catted y pipe into a high flow (2.5” to 2.75/3” mandrel bent - in 2004 and up) off-road y pipe to complement your shorty headers and give your explorer a nice and clean rumble while freeing up a few ponies and picking up a mpg or 2 😀…