hey all so one of the cats on my 01 dakota kicked the bucket all of a sudden i started my truck and i herd a nasty rattling sound crawled underneath and listeded to find that there is something in the y pipe that is rattling inside my guess is a piece of the cat my question is i have been thinking of straight piping my truck for a while will it throw a code without the cats being in ? i dont have to worrry about emiisions laws where i live also any power gain loss? fuel economy? these are some of the things i was thinkin about befor i go ahead and pound the comb outta them if the truck will throw a code is there any trick o2 sensors you can buy or are they just a waste of time

 

Ha - I had planned to ask the same question today! My cats are still good - but I'm planning a new custom exhaust in Jan/Feb/Mar time frame & was thinking about removing the cats.

So whats the deal guys - how do you get around the CEL throwing codes when there is no CAT? I know several have done it - whats the trick?

 

ya i herd you can wire in a resistor on one of the wires of the o2 sensors but im not sure whitch one. i also herd you can buy trick sendors but that they are junk.

 

Ok well on the 5.2's you can loose the cat but you must keep the o2 sensor before the cat since it tells the computer how much fuel to dump in. On the 4.7s there is 2 cats one on each side and there is 2 o2's for each side I think thats it(not fimiliar with 4.7's that much) which you cant just get rid of. Now if you loose any o2 you will get a CEL you can put in a resistor and I think that will trick the computer. You can also get a weld in bung for a o2 sensor I would go this route

 

the 4.7s have the 2 cats one on each side. after the y-pipe theres also a 3rd cat. you can cut that one but the two pre-cats are suppose to help the air/fuel ratio. i havn't done it, just what i've read up on.

 

hey so i gutted my cats out on the weekend didnt put a pipe in i cut off the heat shield marked and cut around the welt at the topside of the cat and driller around the inners and dug the comb out weled them all back up and put the y pipe back in the truck iv been drivin it for 3 days now and havent got any codes yet (hopfully wont get any) and as for removing the 3rd cat which it isnt a cat it is a resonator i havent removed that so far so good hop that helps if anyone is wondering if gutting your cats will throw codes i was told that gutting the gats out you are less likely to throw a code rather than if you put a pipe in place something to do with exaust flow and pressure i have no idea if this is true but thats just what i herd.

 

so is it louder now or what?

for better flow i think people weld a pipe in place of the cat, the empty cat has gotta be messing with the flow some.

 

yea definatly louder expesially when u put ur foot into it yead by not welding in a pipe u probly disturb the flo alittle