I am getting my truck back today after all the work that has been done to it over the past 3 weeks, and well, I have always wanted to gut my cats, but have been worried to waste the cats buy gutting them and didnt want to cause a disturbence in the airflow by gutting them, so i figured atleast if i was aching to be illegal and gut them, the least i could do is just remove them, but my question is, will it mess the o2 sensors up? Currently the o2 sensors arnt connected to the cats at all, so my feelings is it wouldn't mess with the truck or would it? I was thinking of just removing the two cats in the true dual, and replacing the segments with pieces of pipe, would that be sufficient?

 

It would work, but aside from making your truck louder, why would you want to remove them? If you gut them, they will create turbulence in the exhaust that will cause backpressure. Removing them will not gain you an appreciable amount of power unless they are partially plugged.

Let me get this straight, you have a 460, that already has a dual exhaust and cats? If this is the case, it means someone has already gone through the effort to build a performance exhaust. My take is to just leave them alone. They are already high flow cats are would not have a significant effect on power so long as they are the correctly sized units.

But to answer your question, no, removing them will not mess up O2 sensor readings or make the truck run poorly.

 

Yes, I want the truck louder. The cats seem to be a tad undersized, but sufficient because theres two of them, otherwise no, if i was only running one of them then it would be to small to handle a 460 if it was a single pipe. Anyhow, my point was i didnt want to gut them, because I dont want to mess up any vacumm the exhaust had worked so hard creating, then just to go into a swirl fast gutted gat, so I figured removing them would be smartest because I could still get inspections if i put them on before inspections, and they would still be usable oppose to gutting them and have the false apprearnce of functioning cats.

These are the ones i have on there:
http://store.summitracing.com/partde...5&autoview=sku

 

I would look into a pair of high flow cats and be done with it. They will make the truck louder and you won't have to deal with emissions stuff. Also, if you don't have an H or X between the two exhaust banks it wouldn't be a bad idea to have one installed

 

Do you have O2 sensors after the cats? If the O2 sensors are before the cats, no worries.

Your putting 230 cubic inches of engine exhaust per converter so I would say your ok size wise with your current converters.

What you could do is gut the cats and stick a small section of 2.5" pipe through the inside of the cats to make the cats look unmolested. The straight pipe will eliminate turbulance and volume problems. 9/10 if someone checks your truck they will just look at the cat cases and not look into it any farther.

Do you have the sniffer test up there in Maine?

I have one of these on my 6.8l. But they are mucho $$$
http://www.afabcorp.com/AFCO_Dynatec..._Code=Cat-conv

You should also get a different sound with those headers and lumpier cam.

 

great point dfk, i think thats the way I will go 4 sure, but how do those cats work? Are they actually illegal or something? As of now there both hi flow MisterCMK.

 

This is just my expieriece but I put a catco 3" converter on my truck and it didnt get any quieter maybe a tiny bit but not much. So you may be disapointed if you gut them and it doesnt sound any different. Maybe be your mufflers...

 

I have an 89 f250hd w/a 460 and I took off the muffler and was not loud at all so I then gutted the cat and wow thing is really loud changed the sound alot though dont really like it that much so now im going to throw a cherry bomb on it to give her a diff tone but I like it really loud

 

Yeah, but did you gut a high flow cat or an OEM one?

 

Whatever you do dont gut those Cats...I have a guy here in my town that says bring him 1 cat or bring a whole truck load, he'll buy them all...He offered me $120 for my cats when I take them off

 

I gutted the oem if I had a high flow why would I gut it I would just take it off then

 

When I had the cat removed from the Capri, I had them weld some of those 3 bolt header flanges on the ends, and had them do the same thing with the pipe section that replaced the cat. That way I can run without the cat, but when it's inspection time, I just roll the car on to some ramps, remove 6 bolts and put the cat back on.

 

now theres a good alternative.