Oldsmobile/Buick Repair: olds cutlas backfires, olds cutlass supreme, throttle position sensor

Question
i have a 1990 olds cutlass supreme.it has a 3.1 multiport eng.it has a code 53 check eng light is on all the time.when i step on the gas kinda hard as in pulling out in to traffic.it misses and the tach gets very erattic. goes from 4000 rpms to 1000 rpms.replaced cranksensor and egr valve.any ideas you may have will be greatly appriciated thanks

Answer
Hi Billy,
Sorry this is so late...I was out of town taking care of some parent plans.
May want to test the throttle position sensor.
Then the fuel filter, and pressure if you have the means.
Here is a link about the codes.

http://www.autotap.com/codes.asp

Good luck,Van