98 Camaro V6 - SO my car will run ok, then it will loose power and bog down. I then smell a strong gas smell out of the exhaust...I think the exhaust.... The check engine light comes on...It reads the P0300 code - Cylinder misfiring. Could it be a coil? The plugs and wires are 6 months old. Again it olny does this once in a while.

Also, if I push the gas down, while in park, and rev it up - at around 4000rpms the engine starts occilating up and down.

Thanks for any help on what to look at!

 

P0300 is random multiple cylinder misfire. Many times due to a lean condition, or to problems with the ignition system. Keep in mind that when a misfire occurs, even if it is due to a lean condition, whatever fuel was delivered is going to be dumped unburned into the exhaust and produce the raw fuel smell.

CONDITIONS FOR SETTING THE DTC
The PCM is detecting a crankshaft RPM variation indicating a misfire sufficient to cause 3-waycatalytic converterdamage or emissions levels to exceed the mandated standard. If the condition is serious enough the MIL will flash. (too much raw fuel going into the cat will eventually ignite. This causes excessive heat that can damage the cat or even start a car fire.

Always make sure the ignition system is in good condition, as it it is the primary source of misfires.
Other things to check if all ignition stuff is OK:

System grounds-Ensure that all connections are clean and properly tightened.
Mass Air Flow Sensor- A MAF sensor output that causes the PCM to sense a lower than normal air flow will cause a lean condition. Try operating the vehiclewith the MAF sensor disconnected. If the lean or misfiring condition is not present with the MAF sensor disconnected, replace the mass air flow sensor.
Accessory Drive Belt-A damaged serpentine belt, or belt driven accessory can cause engine load variations sufficient to set a misfire DTC.
The air induction system-Vacuum leaks that cause intake air to bypass the MAF sensor will cause a lean condition. Check for disconnected or damaged vacuum hoses, for an incorrectly installed or malfunctioning crankcase ventilation valve, or for vacuum leaks at the throttle body, the EGR valve, and the intake manifold mounting surfaces.
Low Fuel Pressure-Perform a fuel system pressure test. A malfunctioning fuel pump, aplugged filter, or a malfunctioning fuel system pressure regulator will contribute to a lean condition.
Fuel injectors-Do a fuel injectorCoil Test.
Water contamination-In the fuel system can cause a single cylinder to misfire as well as cause a random misfire.
Exhaust gas recirculation (EGR) system-Check for a leaking valve, adapter, or feed pipes which will contribute to a lean condition or excessive EGR flow.
Extended idle-Excessive Open Loop operation caused by extended idling or short trip driving may leave deposits on the heated oxygen sensors (HO2S). The deposits cause oxygen sensors to respond slowly to exhaust oxygen content, affecting fuel control and causing a misfire to be indicated at idle. This condition is not permanent. To determine if this condition is causing the DTC P0300 to set.
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IN simple terms... Check your coils, plugs and wires first. That's what always set the P0300 code for my car (coils every time actually). Then move onto the big things