random misfire - 1997 Blazer

noob525

this is my first time doing this I put new spark plugs new wires cap and rotor and my engine light still comes on. and when I go up a hill I lose power and I am not kidding great gas mileage either there is a new fuel pump and a new spider injectors system I put in and I really do not know what I should do I am stumped thanks for helping me out

stever

Sometimes it helps to know what kind of Chevy and the year. If you can get to an auto parts store and have the codes pulled, posting them may help narrow the issue down too.

noob525

It is a 97 blazer LS and the code is po300