i had my motor rebuilt and when i got it back my check engine light was on. i checked it out and it was those three things. i changed my o2 sensor and it still says it is bad. dont have an ohm meter to check air flow meter but dont have the money to just change it and the problem not be fixed. havent had time to change the knock sensor yet. truck seems as if it is starving for gas when i push the peddle half way. if i put it to the floor or just barely give it gas no problems. if anyone has any ideas of what to check other than the airflow meter since i do not have an ohm meter i would really appreciate it. thanks.

what model of vehicle, year, engine type ?

that would probably hepl if i told you. its a 88 4x4 22re.

$3 for an ohm meter:
- http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=90899

just got done using a friends. nothing went over 25 ohms. not sure if i just did it wrong or the ohm meter is crap. i went by the diagram i was given by u in the past.

i tested it wrong of course and my Vb connection is bad. im not sure where it leads to though. i was told by a friend to check my fuses? good idea or no?

Check fuses, yes, good idea. Call it 30 seconds well spent.