right i got a code up for o2 sensor  17511 cars decatted and i replaced the pre cat lambda sensor with a bosch one but the code still there hmmm is this code for after cat sensor 

In a word, no - for info, http://wiki.ross-tech.com/wiki/index.php/17511/P1103/004355

 

What was the connector like under the floor?, may be a broken wire to the heating circuit for the sensor.

what lol 

I mean on the car side of the loom rather than the sensor, as I presume sensor was new?.

yer sensors new BOSCH one seemed ok at 1st then idling felt like was trying to cut out just gave a lil throttle been ok since i dunno wat it can be 

I've just been looking on Elsawin, and to the best of my knowledge, the heater appears to take power via fuse 43 in the interior fuse box. It has got to be worth a look in the morning to make sure that one is ok.

no more code at mo i deleted it and it aint come bk YET !!!!

Unless the sensor is fubar - in which case the code will come straight back - I have found minor faults on sensors take about 1 week/200 ish miles to show themselves again.

 

Do you have an AFR gauge in your car at all?. some people put them in with boost gauges and they can be real handy at times like this

WATS A AFR GUAGE

gonna see how it goes this weekend see if that light pops bk lol 

WATS A AFR GUAGE

 

Air Fuel Ratio   Assume it checks the mixture pre/post cat?

Assuming its a vrs then I believe their fitted with wide band 02 sensors which is what you need for monitoring AFR. So you should be able to log AFR by logging a group in VCDS.

Only problem is I don't think he has it as I seem to remember asking if he had it in another thread, and I think the answer was no - may be wrong but I think so. I totally agree though, that is the simplest way.

well got car plugged in things are pointing to air mass some readings aint right either 

Air mass?  Interesting.  I have a spare should you need it Terry, and the lambdas now removed from the downpipe this morning.

think clive is gonna have to work his magic the mechanic who looked at it say the valve that sits behind the recirc valve may be at fault but he couldnt say  cheers devon dont need lambda