Not sure if they are that easy on the moderns Jamie.
You would certainly need the car up on some ramps as the wire (I think) is right up against the bulk head behind the engine. You can't get to it from the top.
As mangoletsi stated it should arrive this morning and it did, so I've fitted it and the smoking seems to have stopped along with the strong smell of petrol, I hope this has solved the problem.
Is there any way of telling other than an emissions testing machine? Apart from what I've already said, the old one looked ok I think not jet black or anything.
Thanks to all of you who helped me with this problem, I took my car back this morning for a "free emissions" retest and it flew threw it, strange because the garage dude somehow seemed not as pleased as me, I had a grin from ear to ear because it was the lambda sensor.
I wonder could it be because he was wanting to keep my car there all day (thats what it was booked in for fault finding) so test completed and passed, you'd think it would be just a case of handing over the mot along with my keys right? er, no! for 30 seconds work the "free" retest then turned into a £16.45 emissions retest I was not pleased but payed refusing to give him my cheque card just a cheque. Now I have just rung the VOSA dept (gave no names or garage) they said he should have either 1. retested it for free or 2. done a complete retest and charged me the full price, (which they didn't) there is no way I was going to pay for possibly a days fault finding and I told the garage that on friday, I also told them I would try and fix it over the weekend myself (which I recieved a raised eyebrow for) having completed the fix, explained it to them it seems they didn't want to let me go without charging me something hey? The gararge bloke told me the retest would be "free" what he meant was it would have been in with the fault finding costs, so because there was no fault finding done on my car...you get the picture.
I'm quite happy to pay my way, I'm not however happy being ripped off, or treated like a moronic walking cash machine, don't they just hate it when you can think for yourself?