code 43 Knock sensor or Mem-cal chip?

[y2kpa2]

88 2.8l regal

every day when first started after sitting for hours the car will stall and restart and stall several times before running runs like crap backfiring through the intake at low idle with a misfire it seems to clear up with higher engine speed. with the airconditioning on it stalls more frequently and when comeing off the highway and stopping. have a code 43 Knock sensor circuit.

i recently got trouble shooting info from a local autoparts store
results:
1 knock sensor produces a A/c signal 0.34 volts A/c when tapping on engine block with wrench.

2 wiring to KS has 4.96v D/c Says should be around 5.0v

3 the wire that runs from the ECM to knock sensor has continuity

4 the knock sensor produces 4.15k ohms of resistance
the spec. is 3.3k-4.5k

the information then stated that if all tests passed the mem-cal (prom) chip could be the problem
but i would like some input from some one who knows
or has had a similar problem. the prom chip is $100.00 i don't have that kind of money to be wasting if that is not the problem. i also seem to be getting about 30mpg highway??? also puts out code 63 from time to time that code is not for a 2.8l??

Thank you for your help in advance!!