Fault codes never say to replace parts. They only indicate which circuit needs further diagnosis. The sensor will be defective about 50 percent of the time but there can also be stretched terminals in a connector, a corroded splice, cut wires, and things like that. Temperature sensors have an extremely low failure rate. It's much more common to set that code from unplugging that sensor while the ignition switch is on.
A flashing Check Engine light means way too much fuel is going into the engine and the catalytic converter is going to be severely overheated and damaged if you keep driving. Temperature sensors don't affect fuel metering that much so there has to be some other cause for the extra fuel. If there's no other related fault codes, you'll need a scanner that can display live data to see what the Engine Computer is seeing and responding to. Look for excessive fuel pressure, a fuel pressure regulator leaking through its vacuum hose, a leaking injector, even a vacuum leak. With a vacuum leak, the extra unburned oxygen will be detected by the oxygen sensors and tell the computer more fuel is needed. The same can happen with a misfiring cylinder. The unburned oxygen will be detected in the exhaust, and the computer will command more fuel from all of the cylinders. No matter how much more fuel it requests, there will still be that unburned oxygen from the misfire or vacuum leak, so the computer will keep asking for more and more fuel.
Friday, April 6th, 2012 AT 11:31 PM