i have an 04 grand marquis gs and i have some questions about some modifications i plan on changing soon

1. if i change the muffler to a flowmaster 40 will it set off my check engine light or mess up my o2 sensors?

2. if i switch to an aftermarket camshaft will it mess anything up if i use this one: COMP Cams: Xtreme Energy™, XE262H <Br> Stock Replacement, Better Torque & Power

3. is there a performance air filter i can buy that will still work with the stock air filter sensor?

4. is there a way for me to install any kind of turbo or boost or something to increase my horsepower without major prices or modification

5. if i switched out my stock engine for a mustang engine, would the transmission be compatible?

 

I can't shed some light on everything that you're wondering, but I can put in my "two cents" on at least a few of them.

1) Love Flowmaster's, by the way - excellent quality! If you change your muffler, it shouldn't cause any issues with your O2 Sensor or trip your Check Engine light.

5) There's tons of videos on YouTube from people converting their engines in their Crown Vic's and Grand Mark's over to Mustang ones, amongst others. You may have to do a transmission swap, as well, since they are generally column shifts.

Hope this helped! Sorry I couldn't shed some information on anything else!