Civic Hatch FK6 Cylinder Misfire
Civic Hatchback 1.0 Turbo 2017 FK6
Apparently 3 days ago on my way to work, I got flashing Check Engine Light (CEL) and car started shaking a bit. Called the mechanic and he diagnosed P0303 third cylinder misfire. Cleared the code and drove back home but car was clearly misfiring and code came back again.
After recommendations, opened the fuel injectors and cleaned them but problem persists. The mechanic shuffled coil covers, checked spark plugs and shuffled them, still no luck. Finally they did cylinder compression test and third cylinder failed compression test, 1st and 2nd cylinder were at 190psi and 3rd was 50psi. Now Mechanics are suggesting that it's a problem related to Valve and they have to open the engine head in order to clean it.
What's making me confused is if it's a valve issue, then howcome OBD2 erase the check engine light and I can drive the car at nominal speed and light only comes back when it's idle. Even though I shouldn't drive the car at this condition, I have to take it to different mechanics for multiple opinions.
I'm still not convinced that a car with 20k miles can occur a valve problem. I need second expert's opinion what should be done before I proceed.