Ok,
Think you are goiung to have to speak to garfy regards the ecu and what he did, he may have swapped the loom out for a 2.5.
Look in the suppliers section of the UK forum for links to O2 sensor suppliers, prices range from £30 - £65 .. the cheaper ones require you to cut off the original plugs and solder/crimp onto new sensor lead.
Pics follow of breather pipes... Ensure the PCV valve is working correctly, shake it it should rattle, you should only be able to blow through it one way, towards the inlet manifold. You are interested in the RED, BLUE, GREY and BLACK pipes in the picture.
