1999 Mitsubishi Eclipse Trouble diagnosing the problem.

I just recently bought a 1999 Eclipse Gs turbo charged show car. The engine is actually built almost identical to that of a non-turbo the only difference really is the turbo itself. Anyways I without thinking started it with the auto start on the key chain in gear. The e brake was on at the time and my car mad a fun sort of whine and turned off. Ever since then I have been having trouble with a misfiring cylinder. It is cylinder number four. The codes that are coming up on the computer scanner are Map sensor voltage too high and EGR flow malfuntion. I would like to know what I should check first and what my the problem could be. At the same time a friend told me he believed it could be the cadillac converter causing this so I dont know what to think. Do you believe the map sensor is setting off the EGR or vice versa? I need to get my car running because I am a busy person can you help?