My 1992 chevrolet silverado failed emmisions?

[James S]

Heres the results
ASM2525 TEST CURB IDLE TEST
LIMIT READING LIMIT READING
HC ppm 52 85 200 70
co% 0.29 0.05 1.00 0.00
NO ppm 735 522
RPM 1590 valid RPM 681 valid
dilution 13.7 valid DIlution 12.8 valid

I have installed a new pcv valve ,new plugs, wires, cap, rotor, any other suggestions the truck runs good other then a little bit of low rpm hesitation, thanks in advance for any help

 

[TonynNC]

Replace the O2 sensor.