codes need help

[94toyo4x4]

I have a 94 toyo 4x4 22re manual trans. I have just completed a full rebuild and now I am getting codes 24,31,and 71 showing. The engine seems to be under powered and after running for awhile it starts to idle rough. Any ideas on where i should start with clearing up these codes.

[Brian R.]

24-Open or short in Intake Air Temperature Sensor signal.

Probably disconnected sensor. Check sensor connector, sensor function, circuit continuity/short


31-Air flow meter signal or vacuum switch signal. Open circuit in Vc signal or short circuit between Vc and E2 when idle contacts are closed. Open or short in vacuum switches.

Check air flow meter and circuit for open/short
Check vacuum switch for function and signal
Check EGR vacuum switches (VSV for EGR)

71-EGR has temperature below level during EGR operation. Open circuit EGR gas temperature sensor signal (THG).

Check EGR valve - clean <=First Thing
Check
EGR hose
EGR gas temperature sensor and circuit
VSV for EGR and circuit.

[94toyo4x4]

Brian thanks for your help I was able to get the codes fixed as far as i can tell( the CEL hasn't come back on), but the engine still seems to idle rough after it warms up and has been driven for awhile. It almost acts like the idle is set to low, but i set the idle at 850-900 rpms. any ideas, thanks.

[Brian R.]

Dirty injectors?
Dirty IAC valve?
Dirty EGR valve?

What did you do to get the codes "fixed"?

[94toyo4x4]

keep in mind I am no mechanic by any means. I am not really sure what i did except I rechecked all sensor connections and cleaned the EGR valve as best as I could. I then cleared the codes and they haven't come back.

[Brian R.]

Cool - Mechanic or no mechanic, that's the kind of feedback we want to help others solve the same problem (at least to the extent you solved it).

Put a bottle of Chevron Techron injector cleaner into your gas tank and see if that helps. Clean your air intake and IAC valve.