my buddy wants to cut the cats out of his 03 4.7, and is wondering if there is any way to make that light go off

 

o2 simulators or retune

 

not sure tho 4.7 is dodge right so im not 100%

 

There is no retune as of yet that will do it.... I doubt that the 02 sims will work either... I am fairly sure that the PCMs used in the 5.7 and 4.7 are of the same type and they are too smart for our own good.... every so often the PCM will send out a random rich or lean mixture just to see what the 02 sensors, front and rear will read... the signal has to be dynamic, a mechanical sim will not read what the PCM expects to see and you get the MIL...
some have had luck sticking the rear 02 in a bottle or a blank bung but there are only a handful that it works for.....

TJ

 

A little trick you can try that cost very little is, buy a spark plug anti-fouler (found in the help section) the same thread as the O2 sensor and drill out the middle section to fit the O2 sensor end(7/16) put the O2 sensor into it then put the setup into the O2 sensor bung. Plug in the O2 sensor and drive. I have a 03' Ram with a hemi and it has worked for me. I will pull an occasional code if I sit and idle or just put around town. This only happens because of the bigger cam, I just erase it and keep driving. When I go on long drives or hammer down to clean it out, I won't get a code. I hope this helps!