I've got a 2003 S-10 with a 4.3L engine with 64K miles on it.
It started to run rough today and shortly after that the check engine light came on. It ran very rough at idle but wasn't too bad going down the road. I went home and hooked up my scan tool and got a P0303 code. The cap and rotor were replaced about 2 months ago so I looked at the wires. The wires showed some wear so I replaced them. When I started the truck it ran a little smoother but was still rough. I got a P0300 code then. The truck is still rough at idle but not as much as before. It lacks power and the check engine light comes on every time I accelerate hard. I put a cheap autozone cap and rotor on it before so I got a new cap and rotor and tried it again. Then I got the P0303 code again. It seems to smell like gas too like it could be rich, and it sometimes hard to start. I bought a set of spark plugs to put in tommorrow since it probably needs them anyway.
Anyone have and suggestions of what it could be or how to find out?