No you won't, I just went through this like 2 months ago. I had an off road x pipe on and then I put on the stock one with cats and everything was fine no cel or anything. Just remember to disconnect the batt and to run the car a few hours after puttin the midpipe onHello everyone!
I am thinking about installing a non catted x-pipe on my 96 Mustang GT along with the MIL eliminators. Now, I live in California where I can't have that on to pass smog, so I was just going to uninstall the x-pipe every 2 years and smog it and then just re-install it but my question is, will I have any CEL lights that come on after I install the stock h-pipe with all the cats again?
Sorry, I'm still kind of new to working on cars and what not. If anyone is in the sam situation I am, I would love to here how you deal with it!