DW42
Does LH 2.4 injection have a limp home mode, where it sets the fuel-air mix to a constant when the lambda light is on? The reason I ask is that my tatty 240 sedan, which gets to do all the dirty jobs while the wagon sits gleaming in the garage, keeps getting the code for signal missing/faulty from coolant temp sensor. Replacing the sensor, then the connector and wiring all the way to it didn't fix it. The car seems to drive normally when the light is on, and the spark plugs are not getting fouled. Temp gauge acts normal. Sometimes the code flags up with a second one, for the oxygen sensor. My feeling is to forget it -- but I'm not sure whether the plugs will foul eventually from a rich mixture.
I'm not a big fan of limp home mode technology. My 1995 Mazda van had it on the auto trans. When the electronic valve body developed a minor intermittent fault it locked the van out of top gear -- sometimes while cruising at 110. Quite a shock, if you don't expect it. And for the car behind, which would get enveloped in a cloud of black diesel soot.
ramrod
There is no limp mode, but you need to check why the codes are happening. There could be damaged wiring further down the harness, somewhere on the net there is info of what the volt readings should be when you pin out the terminals at the ECU. What code numbers are you getting? You should also test the o2 while you're there. Any vacuum leaks that you know of?