97 crown Vic

I have a 97 CVPI that starts right up no problem, but it runs kinda rough and doesn't have gas response, it will pick up speed slowly but kinda feels like its an air-fuel mixture problem,I was told it was my catalytic converters then my mass air flow...replaced both but still runs the same...sometimes when I'm standing on it pretty good,just before it changes gear it will get little spurt ,(hi rpm) like it wants to run well then changes and back to running rough... Could it be my crankcase pos. sensor? What does this actually do?...any help would be greatly appreciated !

Have you had the car scanned for any OBD codes? AutoZone, O'Reilly, and Advanced Auto are a couple of nationwide auto parts places that will do them for free. Once you get the codes, you can Google them to see what the problem could be. (I once had one for a "Bad O2 sensor". Turned out to be a vacuum leak.)

I had a guy in the neighborhood whose car was running bad. He said the engine light never came on. I ran my scanner and pulled 8 codes. The dash light for the Engine Check light was burnt the whole time. I replaced the light and then starting checking the problems. Then we got things fixed.

This may help out some. http://www.fixya.com/support/r7995890-diagnose_engine_surges_stalls

The scanners start out pretty cheap. (You can get one free at Harbor Freight with the coupon.) At least get a scanner that allows you to reset or clear the codes. Also, I would advise having a manual. Haynes manuals are almost the same as Chilton. You can also check one out at your library to help you see how parts come off and are re-assembled.