1998 Chevy Malibu Problem

I have a 1989 Chevy Malibu. I recently changed the intake manifold and encountered a problem when I mixed up the push rods. Two were replaced in the wrong location and after taping the engine over to check for a gas leak I had at the fuel rail; I discovered I had bent two push rods. I corrected the order and replaced the two Push Rods. Got everything hooked up and started the engine. I found that the engine runs but will not idle properly. When pushing the accelerator nearly open the engine dose have some sight back fire. It seems that the timing is a little off. As well, the air fuel mixture dose not seem to be correct either I am wondering it there could be a problem with the (PCM) Power train control Module? Does anyone have any suggestions? How is the power control modal tested? I used an (OBD ll ) scanner to pull up any codes and the only codes were low voltage to the map sensor and the other was a Mass airflow problem. I do not believe that the engine has something wrong with the valves but anything is possible.

Help anyone?

hi there
i have heard about this porblem i would try
to change the map sensor that you talked about with low voltage because that can cause a driveablity problem. and i would also go over the connections and make sure that there are all connected it is easy to miss one these days.