1998 Crown Vic Hesitats after wash

Okay I have a 1998 Crown vic Police. I washed the car three days ago unknown to me there was a whole in the front drivers floor board after leaving te car was the car was hesitating and stuttering. I figured the motor had gotten wet and needed to dry back off. While taking the car home the floors started to smoke Pulled over and at that time the car burst into flames. I quickly realized that the whole was there and the catback had caught the carpet on fire. Got the fire out but it cost me tha front carpets. So the next day I replaced the floor pans And carpets. Now since the that point the car will not run correctly. It idles fine but when it is put under pressure the car stutter and misses as if it is not getting fuel. I have replaced all the coils and plugs. I have also replaced the air filter and pcv valve. Evereyone that I have talked to says that it is a fuel pressure regulator but I was wondering if I should be looking something else.
Any help Would Be greatly apperciated

A plugged catalytic converter will choke out a 4-cylinder engine, like a potato in the tail pipe.

It's not just about fuel for 250hp, you need Air too!

Are you getting any DTC's?

A bad MAF sensor and dirty throttle , could give the same symptoms.

Hook up a vacuum gauage. If it takes a few seconds to build up vacuum to around 20psi, then it is likely a clogged cat. Also, did you wash the inside of the engine bay? If so, make sure the spark plug boots are dry.

A plugged catalytic converter will choke out a 4-cylinder engine, like a potato in the tail pipe.

It's not just about fuel for 250hp, you need Air too!

Are you getting any DTC's?

A bad MAF sensor and dirty throttle , could give the same symptoms.
Thanks for the input no I am not getting DTC's. So the plot thickens I took the car to ford yesterday and they did there world famous 200.00 check. The best thing of all is that there head Mech could not even tell me good waste of money! They said that everything checked ok cat sys vacume pressure fuel pressure. Well there was no problems yet when there Head Mech took the car for a road test he came back and with a dumb look on his face told me QUOTE " That car is missing " I sweare to god i wanted to kill them all. Any ways so that is wear I am Even ford has no clue. This car was a Great Vechical Untill i Washed it. I am Going to replace The MAF sensor And see if that makes a difference. Will get back to you today.

Hook up a vacuum gauage. If it takes a few seconds to build up vacuum to around 20psi, then it is likely a clogged cat. Also, did you wash the inside of the engine bay? If so, make sure the spark plug boots are dry.
Had The cat sys Checked it all came out ok thankyou for the input. If you could think of some thing else than please let me know.
Thank you

check the connections at the fuel injectors. Does the 98 year have the COPs or distributors? If it has the COPs, ensure the connectors are also snug on them. If you're unsure whether or not they got wet, remove them, clean and dry the boots out, and put dielectric grease on both ends of the boot to prevent moisture from getting in there - they are very sensitive to it.