any good garage will be able to plug in a diagnostis code reader and tell you what is faulty.or argos sells a code reader for £40 providing that your car is post 01,but reading code's and understanding what to do with them is two entirely different things.However ,armed with the codes,u have a better chance.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix cars.