cheers mateMeasures the gases in the exhaust and it used to regulate and check the ratio of Fuel injected to air. Important bit of kit and you will have no end of problems if it is US. They are charging you ?300 because they are called stealers and that is probably the book price for replacing one
I'd check out a price from your local VW independant specialist.
Thats Windrush VW Pricing in Slough mate ITs a Golf V5, not sure which probe it is - there is 2 !!?!?!?
It was all charged at book time & we are one of the cheapest VW dealerships in regards to labour rates.........be very surprised if you could get it done much cheaper from another dealer?157 still sounds too much to me. To give you a better idea i'd need your engine code! 
Well the price came to ?331 including VAT, and they never even washed it.I recently replaced the front Lambda probe on my 2002 V5, it was ?108 inc VAT for the part and took 5 minutes to fit !!!. The only slight complication is that you need VAGCOM to reset the management system after the new probe is fitted (another 5 minutes).
?331???? Christ, that's ridiculous, well OTT mate! But on the other hand, you should be glad they didn't wash it.. I've heard many stories of dealers washing cars when they're brought in for repair, then when the owner comes to pick it up, there's a couple of new scratches here and there!Well the price came to ?331 including VAT, and they never even washed it.
Right mate, i'll give you two top tips to help you from getting fleeced in future!! Christ I hate VW dealers with a passion, and each time a little fault appears on my VW, I'm paying out hundreds and hundreds.
I know it probably goes against the grain of this community, but I'm at a real crossroads as to wether to keep this car or not, becuase
I can't afford for stuff like this to keep happening on a 4 year old car