1997 Chevy Camaro

So my car is misfiring I replaced the spark plugs and all the little things. My service engine soon light is on. So while im driving sometimes it runs fine but it seems like if I drive it for too long thats when the misfire starts happening. The car will start spitting at around 60 mph. Somtimes itll spit a few times then sometimes itll do it really bad. When I come to a complete stop like at a stop light my car just dies and the check gauges light comes on. Sometimes it starts back up right away and other times it wont start at all for a bit. When I keep trying to turn it on it starts to smell like gas. Also sometimes if I put the car in park the engine will start reving a bit like someone is stepping on the gas. If I step on the gas to hard the exhaust will make this loud bang noise which is prob because of the misfire I dont know. My friend said it sounds like your car cant breath thats while its idling like that. If you have any ideas please let me know.