[MDV6er]

About a week ago, I drove through a gas station. I did not realize how high one of the gas tank ground covers was and I drove over it and smacked my driver's side header. It's scuffed, maybe moved a little, but not much. Continued driving and received p0056 and p0160. However, car still would run fine. I'd push it with no issues. Only difference was a slight rattle frpm the o2 sensor and the cold start high idle was very choppy.

Now, I'm vacationing in ocean city Maryland. Every time I get into it (NOT RACING, COPS ARE EVERYWHERE), right around 5k rpm's the car shutters and starts sounding like a subaru. I was told this is called limp mode and its only firing on 3 cylinders. Today I just jacked my car up and replaced the o2 sensor with a brand new one. The cold start was smoother like normal, but the same effect of car losing power after 5k... No new codes but a cylinder 5 misfire. Also, if I'm driving and go past 5k and it limps, I can turn the car off while crusing, turn it back on, and continue driving like nothing happened.

Advice, tips, help, please.

Excuse mistakes, I'm on my phone