I've got a 2000 4.2L V6 w/ 146,000 miles. After I crank it the engine runs fine for a few minutes then it gets to running really rough. The check engine light came on so I took it to AutoZone and they said the codes are reading "Lean Fuel Mixture" Bank 1 & Bank 2. What can I do to make sure this is my O2 sensors before I drop $250 replacing all of them. Could it be anything else?

 

Check your fuel pressure, the last time you replaced your fuel filter was?

 

What is the ideal pressure?

 

Bump...what pressure should we be looking for?

 

My guess is it depends on the application. road/highway driving are different than off-roading. where did this happen?
also, its a pretty old one. so before you go for changing the O2 sensors and actually spend some on it, I guess its also worth if you check the fuel line, maybe its causing the problem. hope it helped rather than further complicating it.