Truck is 2006 Explorer 4x4 4.0L

Whats up guys. About a month ago the CEL came on showing P2195 O2 sensor running lean. Had it replaced as it wasnt working anymore. CEL came back on a week later for the same thing. Mechanic looked at it and said everything is running smooth and not worry about it as they sometimes come back on and need to be driven a little to clear it off completely.

A week ago the truck blew the coolant thermostat housing (dont think that had anything to do w/ the code) Was such a mess with coolant spewing everywhere w/ white smoke. Had that replaced with a new thermostat and had the mechanic check out the code again. Said everything is perfect. He cleaned the MAF. Said the next step would be to check the EGR or fuel pump. He cleared the code.

The next day, it came back on. What else could this be? Ive done some research and saw it could be a leak in the intake manifold or something w/ the MAF, but he cleaned the MAF. Code is showing the truck is running lean but only stating P2195 O2 sensor.. Could it be a leak in the intake manifold? Mechanic did state he checked all hoses.

Any suggestions? I'm at a loss here and dont know where to go next.

 

P2195 Ford - Lack of HO2S-11 Switch Sensor Indicates Lean 2 | Add Comment

Possible causes
- Faulty Front Heated Oxygen Sensor Bank 1
- Front Heated Oxygen Sensor Bank 1 harness is open or shorted
- Front Heated Oxygen Sensor Bank 1 circuit poor electrical connection
- Inappropriate fuel pressure
- Faulty fuel injectors
- Intake air leaks may be faulty
- Vacuums leaks

 

1. Change mechanics. At this point in time, he should know the function of a CEL better than that.

2. I know you have posted elsewhere, but I'm betting you've got a vacuum leak opening up somewhere. Not sure of the common leaks aside from intake manifold gaskets and injector o-rings on the 4.0L, though. Some of the folks over at ExFo have mentioned actual O2 sensor harness damage tripping that code.

http://www.explorerforum.com/forums/...ighlight=P2195