P0303 Chevrolet -

Question

it has a gas smell when you first started

Answer 1

P0303 Misfire number 3 cylinder

Fuel smell, That should be able to take a visual insection for the fuel smell such as the fuel injector. and the fuel pressure regulator.

Cylinder 3 location would be the cylinder in the back middle, The first is to find out if the fuel smell is from a leaking fuel injector, or leaking fuel pressure regulator.. Checking the fuel injector for fuel around the fuel injector it can usually beseen with the engine running at a cold start up, if the fuel injector has sign s of fuel leakage the injector would require replacement and the fuel injector seal.

The fuel pressure regulator should also be check with the engine running pull its vacuum hose connection if fuel comes out, the fuel pressure regulator diaphram is ruptured and would require a replacement.

 Sparkplug inspection should be made for the number 3 cylinder and note its condition a cylinder that does not have ignition spark due to a faulty sparkplug wire or faulty sparkplug will leave the cylinder wet with fuel, or a  low compression of that cylinder will also cause that condition .