The O2 sensor is mounted in the exhaust manifold to monitor how much unburned oxygen is in the exhaust as the exhaust exits the engine. Monitoring oxygen levels in the exhaust is a way of gauging the fuel mixture. It tells the computer if the fuel mixture is burning rich (less oxygen) or lean (more oxygen).
There is no other way to say it: Legoland is the worst value for money of any theme park bar none. It's hard to know where to start: the Â£132 admission fee for a family of four, the Â£15 per person for the queue jumping system (that's free at all Disney parks), or the cynical Â£2 charge to leave the car park!
So I gathered up the Ten Biggest LEGO Sets Ever from one specific archive just to show that, a) LEGO can be frustrating and cool at the same time, and b) Star Wars has its tentacles in everything. Enjoy! Available on eBay from anywhere between $300 and $600, the New York Skyline is one epic slice of LEGO Americana.