WHAT CAN BE THE PROBLEM?
( I JUST BOUGHT THE CAR BEFORE I RAN INTO THIS PROBLEM ). Long story short , I had a code of a misfire on cylinder 4 P0304 took it to the mechanic shop because it was to the point my check engine started blinking & the car started stalling. First thing they did was the mechanic performed a compression test on every cylinder and it turned out to be around 97-100 psi. The mechanic told me that it can be a cylinder head gasket problem. I told him ill leave him the car for him to check it further more before actually quoting me for a cylinder head gasket replacement. I came back a week later & the main mechanic told me that it was the fuel injector & he replaced it. I said ok & went for a test drive , I still felt the vibration while idle at a red light & like the engine having a quick 1 sec hiccup. As soon as I entered the highway & hit into the 60’s mph , I got the check engine light back on so I took it back. The mechanic scanned again & said its the same thing so he told me go to autozone & get a cleaner fuel injector dump it into my gas tank & drive it & come back if the check engine came back on. I am a decently knowledgeable human being & I knew it wasn’t going to work but I did end up driving it & of course the check engine light came back on. I told him look ima leave it to you again so you can take a look. Came back again today , he said its fine but didnt mention what he did , just said he check everything & its good. I went on the highway with him , still the hiccup with the engine & shaking/vibration while idle but drives fine nothing crazy. So I told him if i have the check engine again , ill bring it back. This time im thinking of getting all my money back because i feel like they not actually fixing the car & just saying stuff.
Sorry for the long explanation, just trying to give you guys all the info.