Hi all

Mk6 fiesta 1.25 16valve tried to get upstream lambda sensor out soaked with penetrating for over an hour used proper sensor socket with Terry clip around it to give more support and a long breaker bar but it won't give I can feel the socket twisting ,any ideas on next move apart from going to a garage ? How do they get them.out ? All I can think of is break the top off and use a right angle impact driver and a conventional socket but it's a bit drastic and if it don't work then the car is stuck undeliverable any ideas?

Penetrating fluid needs to be left over-night ideally.  Some are better than others, I prefer Plusgas to WD40.

Garages will probably use a blowtorch to heat the area around the sensor which should expand the hole slightly and break the rust.

Thanks Tom

I used shock oil which freezes the  nut or sensor and shrinks it slightly to allow the oil to penetrate it always serves we well but I'll try plus gas overnight if I need to.I measured the values on sensor and plug and they all appear ok so I gaveem a good dose of contact cleaner even though they seemed clean and eml.has gone out ! see how it goes I suppose but I hate things like this where I can't see a definitive work or no work

If you don't have access to a blow torch running the engine to full operating temperature help? Not just idling, but give it a proper Italian tune-up for a couple of miles before then retrying the removal (being careful not to burn yourself of course!). 

As an alternative, you could cut the wire (to allow repair/reconnection afterwards if it doesn't work), slide a decent ring spanner over the cable and sensor, and then apply the torque multiplier technique of hitting the other end with a lump hammer to get it shifted. The impacts themselves will really help break the bond. 

Thanks both food for thought !! I did think about running it to get it hotbutwondered if the sensor would expand and still be jammed

 

I've previously had success just using a decent quality double open ended spanner (22mm?) with extra leverage from another large ring spanner.

Not sure whether you would have sufficient access to do that on your car.