You should not have gone to the dealership in the first place. Compression test in that engine does not take very long so over $500 to do a compression test is just flat out ridiculous.
And his BS about parts is another thing, they’re just trying to sucker you up into an expensive repair that you don’t need.
When was the timing belt replaced last? Because if the belt jumped a couple of teeth it’ll cause a misfire only on one bank. Ditto if it’s stretched out enough that bank 2 camshaft is following too late.
The fuel could be a problem and the computer only set a misfire on two and four and it could actually still be misfiring on one and three.
I suggest you tell the dealership to go to hell and find an independent who knows what they’re doing.
