Ford Focus ST, 2005 zetec climate 1.6L - Is a garage ripping me off? Ford focus (05) lambda - sivyer2081

I just got my car back form a garage, they said that my ford focus (2005 zetec, 1.6) has 4 lambda sensors 2 upstream and 2 down. Is this true?

I had a engine management code says that blank 1 sensor error. The garage said they changed one of the sensors. There are two sensors just behind engine block in the exhaust manifold, but it doesn't look they've actually changed any of them!

There are corrosion on both sensors. Is there a casing that they would have put around the sensor or should it look new? If they haven't changed it what's best to do?

Thanks in advance for any help!

Ford Focus ST, 2005 zetec climate 1.6L - Is a garage ripping me off? Ford focus (05) lambda - Collos25

http://www.lambdasensor.com/main/ford1.htm

As far as I know they only have one but try this company and ask they will know without doubt.