As a kid I always did the work on my nova, 1972. Now that I'm 50 and vehicles are more complex I have not done any work in years. I want a tune up on my Colorado, 2004, 3.5 liter. Nothing in the way, I have the air intake without resonator box so plugs are easy to get at so is it worth trying or do I pay 300.00 + dollars to have it done. I need more acceleration.