yes it will put the check engine light on. The sensors detect not whether or not the cats are ON, but whether or not they are working... gutted cats don't do there job (they dont "work" essentially) which is picked up by the rear 02 sensors.
You're BEST off (if that makes sense) by running gutted cats and MIL eliminators for normal street use (minus inspection of course, unless you're lucky and only have to pass visual, not the butt-sniffer test )
Why? Because gutted cats will protect you from the all too common "cop on his knees with flashlight, checking for cats because he's pissed off your car is too loud", where as, striaght pipes ("race pipes") will just get you into trouble (most) of the time.
Regardless of what you choose, MILs will be required if you have, for any reason, non functioning, or non existent cats, or else you can stare at the check engine light (which isnt good, becuase if something really goes wrong, you wont know).
what do you mean you "cut them off"... you mean you removed the stock mid pipe, cut the cats out, and sectioned and welded in straight pipe to the STOCK? or did you just buy an aftermarket catted H/X pipe w/ hiflow cats??
what do you mean you "cut them off"... you mean you removed the stock mid pipe, cut the cats out, and sectioned and welded in straight pipe to the STOCK? or did you just buy an aftermarket catted H/X pipe w/ hiflow cats??
I had the shop put straight pipe in the place of the old cats. It wasn't necessary to take the mid pipe off.....Kept the cats in the basement in case I ever needed them down the road.
what do you mean you "cut them off"... you mean you removed the stock mid pipe, cut the cats out, and sectioned and welded in straight pipe to the STOCK? or did you just buy an aftermarket catted H/X pipe w/ hiflow cats??
get the bigest screw driver and a hammer and take all your frustration on those cats , the drivers side of the pipe was easy as hell to remove, but the passengers side is a whole complete different story.
it will take you 30-50 minutes to gut the drivers side cat.
the drivers side will take you 2-3 hours since it has that bent.
jbushman is right your check engine light wont come on if you only gut the two pre cats. if you planning to gut all 4 good luck.
if you have state inspections i would recommend you buy a used stock pipe and gutt that one and save yours until inspection. stock pipes go for 50-60 bucks at ebay. if you need to buy a new one from ford it will cost you $2000 yes $2000.
you will get a big sound difference and you will love it since it didnt cost you a thing. if you want some tips go to my page 2 on my cardomain site it has the tools i used. and some tips..
thanks man , today im headed down to muffler shop, gonna ask if they can just cut the two cats off in the front for me and then weld in a piece of pipe to replace it,... sound differnce???