2000 Dodge Neon • 4 cylinder FWD Automatic • 115,000 miles

I recently replaced the transmission in my 200 neon(2.0L). When I started the car it revved to the rev limiter for a couple seconds and then dropped back 1500rpm and started backfiring and missing. It is really loud and has strong smell of fuel. I checked the timing to make sure that it didn't jump. The timing is set perfect. Any ideas on this?
April 15, 2011.

Is the check engine light on? Have you tried resetting the PCM? Unplug it, along with the battery. See if that helps. What type of transmission? If it's an automatic there could be a problem with the torque converter.

Apr 27, 2011.
If the PCM didn't help, check the idle air control valve as well as the throttle position sensor.