Engine starts cold in the morning fine. As it warms the automatic choke revs down rpms, but then engine begins to run rough, but catches and revs back up to high rmp and starts all over. Can drive the truck but it lopes or hesitates going down the road especially when driving around 35 - 50 mph (cruising). Received error codes of 22 and 122. Code 22 is MAP or BARO out of range. Code 122 is TPS below minimum voltage. Did voltmeter check on both and both check out fine per the manual. Pulled both to check for dirty and both are clean. (cleaned them anyway) I did a visual inspection of the vacuum lines and they seem to be fine. Except for pulling each and every line and checking them seperately, I'm stumped. Any help is appreciated. Thanks.

 

Have you ruled out the possiblity of a faulty oxygen sensor? Try running the vehicle with the sensor wire disconnected and if it runs better, the sensor may be bad.

 

Do you have access to a portable oscilloscope or a meter with a frequency counter? The MAP sensor I know cannot be tested with a simple voltmeter since it gives a frequency output.

 

I don't have an oscilloscope or a meter with a frequency couter. I will look into that. I will also try disconnecting the O2 sensor and see if that works. Thanks.

 

It appears to be the O2 sensor. I disconnected it and all if well, almost. I will put a new O2 sensor on this weekend. Thanks to all.