I'm sure this has been asked to death but having a fun time with my envoy. Miss fire on cylinder 3. Changed plugs, coils, and checked compression. Cylinder 3 is lower around 110 but my mechanic says it's still in range. Miss fires only at idle, and occasionally has a surge of power also only getting around 13 mpg on the highway. He wants to try changing the injector before we tear apart the head or block for the lower compression. Any thought or recommendations?
