Past couple days I've been having a ticking sound when I push down on the gas. The harder I push on the gas the louder it gets. Could it be a misfire? The other day it backfired which gave me the idea the gas wasn't being ignited. I checked the wires and plugs and there good so possibly the fuel injector isnt working correctly?

 

I replaced the spark plugs, wires, cap and fuel filter and it's still there. Could it be a valve clicking? Would an oil change with thicker viscosity fix it? Thanks

 

You need to spend a little more time isolating the exact root cause of the noise. Could be a bit of lifter noise or a noisy injector.

This is where a "mechanics stethoscope" comes in very handy. Looks like the ones the
doctor uses to listen to your heart and lungs except it has a filtering device on it to take out some of the harshness.

In a pinch, use a dowel or even a long wooden screwdriver.