Professional mechanic.P0303 code
Spark plugs loose
PSA: If you smell exhaust/fuel in the cabin
Fuel smell in cabin and engine compartment?
Advice from P303 thread missing ground electrode: "avoid running this engine any further and first endoscope the cylinder to see if that piece is still in there; if so attempt extraction (vacuum/magnets) and inspect for damage to every surface inside the cylinder. If no obvious serious damage then compression test. If you're lucky it eroded over time (could be a couple issues) or if it was a solid chunk off somehow got shot out the exhaust before extensive damage..."
Edit: is that a mechanic showing those plugs to you or is this friend/family DIY work?
The mechanic just replaced the spark plugs and wires and its good to go. I was wrong to panic. All good...