GolfmanSpeck

Well I shouldn't needthe MILswith the stock cats. I didn't chack to see if i actually have the MILs yet but I bet that they were installed with the offroad h-pipe andnow thatthe stock cats are in i am getting thethe P1131 code because the MILs are probably still in. I will check on that this afternoon and post about my findings. Anyone else have any comments or suggestions?

sweet99

You are correct. What you do need are 2 more O2 sensors that go after the cats. Perhaps the guy you bought the car from has these MILS in their place. Hey guys what are MILS, is that an acronym for something? I do think I have read about poor quality MILS or perhaps they are damaged? Try a search for MILS, I am.
Sounds like you need either good MILS or O2 sensors there. markPS: Rob I see you found what MILS are, please clue me in. I know they are used to trick the ecu and likely send a voltage reading tht falls within the spec the rear O2's should read if the converters are doing their job. Thanks

GolfmanSpeck

So as much as I know is:
MIL = malfuction indicator light
The product is a MILs Eliminator, it is used for the back to O2 sensors (not sure what the actual components are) when you are running cat-less, to trick the PCM to thinking that the cats are working properly. They are used to "Eliminate" the check engine light that would come on as a result of not having cats.

sweet99

Well then the mid pipe has either MILS or O2 sensors. Ithink O2 sensors wuld be ebst considering you have cats but I would think the MILS would still send the proper voltage signal to the computer regardless. Can you contact the guy you bought the car from and se if he has the O2 sensors if you need them? It seems he would have saved them for the exact situation we have here where the stock mid pipe is put back on? mark

GolfmanSpeck

The MILs just go inline before the O2 sensors, so they are still the original O2 sensors. I got under the car yesterday and found that it had homemade MILs on the car, that were very poorly done. I am surprised that theywere workingbefore I bought the car. So I cut them out and put the O2s back in. I will see if that solved the problem.

sweet99

The stock mid pipe has 4 O2 sensors and the MILS to my knowledge go AFTER the cats. The motor would still need the front O2 sensors to run properly. Check it out as I do believe I am correct on this. Good Luck, mark