FINALLY REPAIRED, spashed out & bought a rear nox sensor from audi £131.00 plus vat approx £157.00 january 2012 (part only). has been fitted for a week and half - no probs anymore no dash light or code coming back up - brilliant.
I followed chb instructions very good indeed i have to say & many thanks), cut the old wires where the grommet on floor plan is (underneath and slided off the grommet) and put the wires threw my ring ended spanner so i didnt slip on sensor nut to take off. my other trick was i removed grommet in floor underneath car after disconnecting, connecting plug inside car, pulled wires inderneath car so they was enough old wire to knot around new inside connector and wrapped it in electrical tape to protect and from coming apart then pushed it threw tight hole and pulled old plug (which had moved towards the hole and under a mass of wires) from inside car which made it alot easier then removed tape and plugged in the new connector towards end of operation.
replaced at 58,000 but had the problem for 18 months or so, its my partners car (think its mine as i do all the spending on it) but dont think she likes me playing with it to much, she seems impressed its fixed. at 1st started flasing for a while, then went over to a pernament light. removed code a few times to make sure it was 100% at fault. 1st major thing i had replaced on this a2 not been a mechanic but it did help doing it on a pit maybe if you have access to a ramp but wouldnt other wise try to do it at home unless you have good ramps etc.
