My 2004 civic starts and then stops . Its sounds like only 1 or 2 cylinders are firing and smells of gas. I can also hear air escaping somewhere. Any ideas?

Remove all of the spark plugs and test each cylinder's compression with a gauge. Write the results down on a piece of paper. If the engine has overheated, for instance, the compression test will tell you whether the head gasket has blown or not.

This link may also help:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-11.html#post2123675

Thanks I will do that . I appreciate you taking the time to answer.