Getting code 172 and 181. Any idea what these are? 172 is HEGO sensor fault/lean. 181 HEGO sensor fault unable to switch / lean during part throttle. Ive looked online and cant find a definate answer.

 

Sounds like your 02 sensor is detecting a lean condition.
Often that can be a low fuel pressure condition. Start with a fuel pressure test (gauge) first I would think.

 

Could it be the fuel filter? Also my idle is high then low then just right. Changed my EGR the vac line and the sensor, the tps, o2 sensor and the iacv. Nothing has fixed this problem. But I did see where the vac line running from the carbon cannister to the cannister purge solenoid was not connected.

 

Fuel pressure was fine almost 40 running and just below koeo. And I did flip switch between tanks. So pressure is good. gonna change filter and regulator.

 

Well I FINALLY figured out what the problem was. Unfortunately it was after alot of replaces that didnt need to be done at a cost of around $400. Turns out that it was a stupid plug. Ive never seen a plug this bad. Carbon and rust all in the concaved area around where it sparks. Idk what its called. Now shes eatin pavement again. Thanks for the help.

 

Where was the connection that was giving you the issue. I am having similar issues with my 94 f150. I can't seem to find the problem

 

This thread has been dead for 4 years. You should start your own new thread with your truck's COMPLETE description & history in your signature as this page explains:

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