Hi all,I'm new here and am relatively clueless when it comes to cars - although I will be eternally grateful for any help / advice you can give me I have an Audi A3 (2003, but new shape - 2.0 FSI Petrol) and I noticed a while ago that the engine coolant was needing to be re-filled around every 150 miles. I took the car to a garage (in London) and they looked around and couldn't find any problems, so they suggested radweld (which they used) and it seems to have fixed the leadking.However, since they did this the coolant light comes on every time I drive the car and beeps a few times and today the engine management light came on too I've read lots of threads today and a lot of them are suggesting that it could be the sensor?! People seem to have resolved the same issue, but I'm concerned that the garage may have done something stupid...I've looked at the oil, which looks fine and there are no visual leaks or impact to the coolant itself.PLEASE HELP...Thanks so much in advance.Paul