My 1997 is doing the exact same thing; I am getting 54 lb pressure at rail, dealer says that sounds low, manual says it needs 60-66 lb to operate correct. I have replaced fuel pump, fuel filter, spark plugs, cap & rotor, O2 sensors before the CATS Camshaft position sensor, still bogs down. My last resort, I am going to replace the fuel injector pressure regulator, because of low pressure I have a feeling fuel is bleeding past regulator. I will let you know my result.

 

Have you checked your hose clamps? I hear a faulty one can lead to symptoms similar to yours......