Hello all I have a 2009 Silverado 1500 LT 5.3 with 93K and she's been acting up the last couple of weeks. The check engine light came on throwing code p0305 which is a misfire in cylinder 5. Bought new plugs and will be putting those in tonight. The code could also be the coil pack or the injector but figured we'd start cheap and work our way up. Then one day I had it in drive while I was waiting on the kids to get out of school and the following service messages popped up: Stabilitrak off, traction control off, service stabilitrack, service traction control. As soon as these popped up the truck started idling really rough. Once I put in in drive and started going again the messages went away. It is now happening every time it is in park and idling. Could the plug/coil pack/injector issues be causing all of this as well? I've read that this is common with throttle body problems but those are usually accompanied by a "reduce engine power" message and then the truck cutting off while driving. The truck also needs new brakes all around and new rotors on the front so could that be the issue? Thanks in advance for any insight anyone can offer!!