GM-GMC: 1993 GMC Sonoma 4 wheel drive, gmc sonoma, catalitic converter

Question
My 1993 GMC Sonoma developed a problem yesterday.  All of a sudden when you give it gas it is very sluggish like there is no power and slowly builds up speed.  It doesnt stutter just ver sluggish acceleration.

I thought it was the Catalitic converter and I had it replaced.  but it didnt change anything.  I took the exhaust system off and put it back on.  It drove normal once around the block and then got sluggish again.

I did a pressure test on the fuel and it had the volume recommended.
Any ideas?

Answer
Need to know what motor in you truck, Also you mentioned that fuel volume was within spec, was pressure tested also? A good general place would be to pull a couple of spark plugs out and inspect them for an extreem rich or lean condition. White is lean and black with deposits is rich.sensor failures are usually gradual so has it been getting worse and worse or was it a sudden problem?