code 22 only at idle

[russ_westrem]

i have a 95 tahoe 5.7 with 100 k miles. at idle my check engine soon light comes on then goes off once i start moving again. the code is 22. thw throttle position sensor. i checked the sensor with an ohm reader and it checked ok. what could be my problem.

[brooster]

Ohm meter is the wrong way to go. Check TPS voltage key on engine off. I believe the signal wire is blue, but the easy way to find out is unplug the TPS. Check each wire. One will be close to 5 volts. Turn off the key check the other two with the ohm meter. The one closest to 0 or infinity is ground, the other is the signal wire. Plug the connector back to the TPS. Turn the key on. Voltage at signal wire should be around .5-.6 volt. If you or someone else has readjusted the idle lower to compensate for vacuum leak (throttle body gasket), the minimum TPS voltage may be too low.

[Bronco2]

Check the TPS voltage output at closed throttle-I think it should be app. .5 volts at idle and 4.5V at WOT. Resistance readings [ohms] are not always accurate due to temp. changes,etc.

[russ_westrem]

well i know for a fact its not the tps because i also bought a new one and still had the same problem. and i also reset the computer after i installed it

[Bronco2]

brooster-just to help with the diagnostic on this-"the wire that reads 0 or infinity is the ground"-not causing trouble,but that seems to be a opposing statement. 0 ohms is a perfect connection,while infinity means no connection.Agree with the restof the diagnosis

[brooster]

Depends on which ohmeter you are using