GMC Repair: 1994 gmc jimmy, oil pressure switch, fuel pump relay

Question
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Followup To
Question -
I am a mechanical moron, I just replaced the fuel pump, fuel pump relay, and the fuel filter on my 94 jimmy (w) engine.  I started it and it ran fine. After about an hour I tried to leave (in the jimmy) and started it and it all of a sudden runs very rough.  When I put it in gear it bogs out and stalls.  I did not touch anything but the relay, fuel tank, fuel relay, and filter.  It acts like a spark plug or two is gone.  Any suggestions or ideas would really help me.

Thank You
chris O'Dell P.I.
Answer -
hello chris
are all the lines tight and is the fuel pump ring tight could be sucking air i would check pete    I tried that, earlier today, I checked all connections and lines.  Everything is tight and all lines not kinked.  I called around and they tell me to replace the oil pressure switch, or replace the cat converter. I am comepletely lost, it is really acting like spark plugs are gone, but obviosly they are not. There is also suddenly a very strong gas smell from the exhaust.  any suggestions.  
thank you for your time.

Answer
hello chris
u want to do this right so it does not cost u a lot of money . i am sure i would get a diagnostiac test this will tell you for sure what it is with out guesing. it sounds like a intake gasket to me but it is better to have it checked pete