So how difficult is it to change a piston ring yourself and what kind of tools do you need? also if a cylinder i low on compression, could there be other problems besides just a bad ring? The car gets about half the mpg it used to. Thanks.

also if a cylinder i low on compression, could there be other problems besides just a bad ring?

Could be a bent valve as well.

Don’t forget the obvious... a not-fully-inserted or cracked spark plug.

Don’t forget the obvious... a not-fully-inserted or cracked spark plug.

Oops, sorry, my bad. That is, assuming you’re pulling the plug to check
the compression.

i changed all the plugs and the condition didnt change so i dont think its that. also, is there a way to get the car from running so rich or is it just a result of the compression being off? Thanks.

Others here will be much more qualified to answer than I, and I’ve
already stuck my foot in my mouth... but I’d guess that it sounds
plausible. The fuel injector’s computer relies on precise information and a
compression fault may throw that data askew.

any hints are better than no hints, i appreciate the help