This morning when i left work the engine management light came on, on my 2002 S3.
I had just finished a night shift so didnt have time to investigate so i drove it home approx 2 miles and went to bed, the car drives normally too btw.
Then when I woke up this afternoon i went back out to see if the lamp was still on, and it was. So i decided to drive to the local Tesco's carpark and call the RAC as if ive just broken down. Lucily the RAC man was actually in Tesco when i called them, so he was with me within 2 mins. He scanned the car using his laptop, and it came up with fault code: P315, which he says is the o2/lambda sensor. The fault code on the laptop explained it was to do with the heating element/wiring of the sensor. He then displayed an instantaneous graph showing the voltage coming from the sensor, with respect to when he pressed the accelerator, and it was not changing. He cleared the light, and told me to replace the lambda sensor.
I have been doing research, and I presume I need the pre-cat sensor, but understand its a pita to replace yourself?
Does anybody have any info on this fault, and/or help with replacing the sensor please?