Hi, there will be two oxygen sensors on your car, one on the exhaust manifold or on the pipe connected to it and the other will be after the catalytic converter, the main problem is due to the heat the exhaust operates at the sensors tend to become seized into the fittings and require the use of an oxy-acetlyn welding torch to heat the old sensor up to a cherry red heat to break the seized threads, the other thing you will need is a correct sized lambda sensor socket this has a cut-out to allow the cable not to get in the way, when fitting the new sensors ensure that the threads have plenty of copperslip grease on the thread to reduce the possibility of them seizing in the future, you might find that a fast fit exhaust place the cheaper place to go too
Paul
December 2009