Help!! Focus won't start after sound system installation

My boyfriend installed a sound system in my 2003 Focus ZTS today, just to the factory CD player, started the car up (which was running fine before this) to try out the speakers and the fun began. It started shaky, it was revving really funny and I could smell gas coming out the exhaust. Turned it off, tried to start it again and it barely started, and now it won't start at all. It does turn over and the battery is not dead, the radio will turn on. The only things that have been touched are as follows: air filter replaced, air tube disconnected and reconnected, wiper washer fluid added, and the wire hooked up to the battery. I looked at it and made sure nothing was disconnected by accident, everything looks fine. Any ideas? I am hoping not to have to get it towed, I am short on cash! Is there anything I can try before I have it looked at? Please help!

It could be not related to recent work. Sounds like the vehicle flooded out which means inspection of the spark plugs would be needed. I would at least start with checking the basics...........

Spark test
fuel pressure test
Check for codes

when your boyfreind fiddles with your sound system he prolly triggered your security system which in turn reset your PCM which you need to let the car run and drive at various RPM ranges so it can re-teach its fuel map... change your spark plugs and let it idle (it will be rough) for about five minutes... give it some gas if you have to keep it from stalling... rev it to about 1200 RPM for a couple of minutes and then take it for a lengthy drive and try to vary engine speed as much as possible so your computer can remap itself

Well, I am not sure that I can completely say that it is not related to recent work. Make sure that the MAF (mass air flow) sensor was plugged back in, or that something foreign did not get into the MAF sensor. It could be a number of things, but also, poor battery connections could allow it to turn over, but not get enough power to the ignition system. I had a bad positive battery cable cause a similar issue on a 2000 Focus, and all looked good, but many hours of labor later, it was a bad battery cable. If there are amps and subwoofers involved, INSTALL CAPACITORS!!! If not, alternators get burned out, and batteries are ruined.