what can cause gas an oil to mix

could have a bad injector allowing fuel into the oil. either that or a bad fuel pressure regulator. you need this confirmed as the engine miss is a big clue as to what injector may be malfunctioning.

Roy

yes it has a bad mis an it shut off on me the othjer day so is it a DIY job that i can do . so how could i test injectors or regulator

you need a fuel pressure testor, voltmeter and test light. if you have never done this before, i suggest letting a shop verify it for you

Roy

got pressure tester an volt meter an have a little mechanic background so tell me how to check it an i would be very greatfull to u so what do i do

turn the key on and see the pressure. should be around 55-60. turn the key off and it should remain there or a little lower. if it drops off to 0 then you have a bad injector. by pulling the code for the check light, it will tell you the cylinder for the bad injector.

Roy

This is a Vortec engine and the injectors are not accessible from the outside. Beside a leaking injector, it's very common to have a leaking regulator or line that will give you the same result.