So got the spark plug replaced in my car. And less than 12 hours later I have a misfire, on cylinder 6. So the shop says it is a dropped valve. My friend that works on Chevy and Fords says it's a blowout from them not putting it in right. So he is saying fix the plug threads and get a new plug or use the same if it isn't bad. He said if it stays in limp mode like it did today around 11am he said get the computer flashed. What do yall think?