Hey guys im kind of in a pickle here and need some advice on where to start on isolating this issue. -for some backstory- I drive my 2012 Civic Si to work every day on the interstate for about 14 miles then back. I've owned the car since October and purchased it as a salvaged title with 45,000 miles on it. The car was involved in a collision (promised it never touched the engine) but after driving it and seeing the damage photos, I thought it was still worth it. She drove perfectly fine every day until now. When I exited the interstate I made a second stop and noticed things just seemed "sluggish" right before I got there. No knocks no pulls or CEL's just a noticeable hesitation. I parked it and ran inside for 10 minutes. It cranked perfect, then when I threw it in reverse, I noticed the body was bouncing and starting to rock. So I reversed fully and continued and as I pulled away it became more and more apparent that it was misfiring. I could still accelerate rather well so I drove it the last mile home and parked it. Ran a quick error code scan and it reported that Cylinder 3 was misfiring. Fast forward an hour and I crank it, It started and idled like nothing was wrong. Drove it 5 miles into town and I can only assume that the engine had become warm enough, It started doing the same thing, barely shaking and misfiring. I parked it for 10 minutes again and cranked it fine, then started having a slight misfire a block down the road. I tried to make it back home but it misfired harder and harder eventually sputtering and crawling to a stop. No smoke, no fumes. No pops or crazy loud noises other than when actually misfiring. Since I broke down in a fast food parking lot, I dropped back by a few hours later to get my stuff out of it and decided to crank it just to check, and VOILA it cranked no problem. I probably could have driven it a few miles until whatever is failing warmed up enough to cause issues, but I left it and will be towing it to one of the yahoos near me that works on cars. I have absolutely no idea where to start but im convinced the engine isnt a gonner. Thoughts?