2001 Daewoo Nubira • 16,000 miles

I recently bought a Daewoo Nubira and the garage bloke said that the engine warning light came on and off intimitently. He said it wasn't a problem and I could leave it as it was but I was concerned so I asked him how it could be fixed. He said it was a camshaft sensor which needed to be fitted and that it wasn't expensive, he would fit it if I wanted. I was concerned enough, having had a cam shaft failure in the middle of the motorway, so I askd him to get the part and fit it. He said he would do it free. He then gave me a bill for £140, saying he had to remove the engine to fit it and that was why it was so expensive. Is this correct as I read that it is about £45 for the sensor and easy to replace/fit, so he's charged £95 for labour. Should this part have been replaced before I bought it? Was it dangerous? I also read that Daewoo recalled cars with faulty sensors and fitted them free?
October 4, 2011.

You've been had-no need for the engine to be removed to replace the CMH sensor-

Oct 4, 2011.