Rep Power: 0

Good evening!
I wanted to see if anyone could help me out and give me their input on what seems to be wrong with my vehicle.
i have a 2006 Honda Civic EX with about 215,000 miles. Car has been maintained and in good condition
I recently started experiencing engine misfiring while driving at highway speeds as well as coolant reservoir disappearing in a matter of days with engine overheating. I had all 4 spark plugs and cylinders replaced as well as a new thermostat placed in my vehicle.
The new thermostat helped with the overheating aspect but my car still continues to go through coolant (coolant does not stay in reservoir tank) and I still continued to experience loss of power on acceleration and misfiring on acceleration at freeway speeds with no check engine light. Today my CEL turned on with codes reading P0300, P0301, P0302, & P0303.

Does anyone know what this issue could be? I’m thinking fuel injectors, filter, pump? Or head gasket leak?

thank you in advance for any help!!

 
Rep Power: 367

I had not heard of this type of overheating in the 2006+ cars.
who did the cylinder job?
so, it is losing though the reservoir?you can try to use same testing method for 7th gen cars

• Head Gasket issue 7th gen cars
• test method for headgasket on 7th gen cars

What was common on these cars were the cracked block, and it would lose through the cracks in the front of the engine.

• engine block cracks

 
Rep Power: 224

Is there coolant leaking? Puddle on the ground or evidence underneath? Even a heater core leak inside the cabin.

 
Rep Power: 222

Coolant may be getting into the cylinders, find an inspection camera and get a look in the combustion chambers. If they look shiny and clean then that's where the coolant is going