I had Pacesetter LTs installed by an exhaust shop. Cats removed, custom y pipe into a 3" exhaust with magnaflow muffler, all resonators gone. Installer had front o2 sensors wired in shop. Back o2 sensor he had something? like another sensor plugged into the back one, like a piggyback. He said it would fool the system into thinking it had cats. Did not work. Throwing a cel. When I clear it with SC 3815, it returns almost instantly. Short and sweet, can I get rid of the cel by buying new mopar sensors, front and back or do I have to do what some of the other people have said. Thanking everyone in advance.

Bettsie

Not to be rude, but there are probably dozens of threads here concerning this issue. Me and the same couple of guys end up saying the same things over and over, maybe we should just write a cat delete sticky.
What your exhaust guy did was install O2 simulators which back the sensors out of the exhaust stream, theoretically minimizing exposure to the newfound pollutants. Works for some, not for others, browse around and you'll find several solutions, you might just have to try a couple until one works. Don't buy new sensors, they are working fine and that's why the code is being thrown. The front 2 sensors tune the truck, the rear 2 are the ones detecting that the cats are gone and throwing the code. Bet that truck sounds mean now, how's she run?

Thanks, it runs really good and is loud as hell. I am going to the track Fri. weather permitting. I will let you know what improvements there are.

You can try adding another sim. You should be able to find them at the auto parts store. There called anti spark plug foulers. Needs to be the same thread size as you cat monitor. You will probably have to drill the sim out so your 02 will fit in. Or just screw the current one into the new one to stack them. And have the new one screwed directly into the pipe and the currrecnt one with the 02 into it. If that doesnt work you can try packing steel wool inside of them also.

yeah,im having the same problem,i just replaced my cats with magnaflow hi flow cats friday evening and saturday i got a check engine light and my mds stopped working,im assuming its the cats,im going to try the sim thing,i avoided long tubes and deleted cats for this reason,guess i may as well have done it.

Thanks for the info . I guess I had a stubborn system. I finally got the cats reinstalled. After dicking around with the sensors, one was now bad,and with the help of SC the CEL is gone.