In the spring I had hesitation after driving on the highway. Diagnostic read code 172 (02 reads lean). Replaced the 02 sensor and drive approx. 1000 miles, and same thing again. Replaced 02 sensor. Seems to be starting to hesitate again, but not engine light/code.... yet. Did I get one bad 02 sensor, or is something blowing them out. Clogged cat?

 

age of vehical?

 

I ask because you may be chasing a ghost....look for a crack in the PCV return hose right behind the throttle body...a commen occurance creating a lean condition

 

should have included this before: 1994 302 107,000 miles box stock also replaced egr when I did the 02

 

Check for vacuum leaks on the intake and the PCV system.

Steve