54 Plate 407 2.2 Litre Petrol, Engine warning light has come on, Depollution system faulty message has come up, engine is in limp mode. Car will start but will not rev, so I cannot try the blast down the motorway or expensive fuel approach as suggested by some. I would very much appreciate any ideas of what to look for to find the cause. Many thanks, Ian
What you need to do is have a scan tool connect to the vehicle to read what codes have been stored.
Guessing what the fault could be can be expensive replacing parts that might not be faulty.
Possible causes are o2 sensor, air mass meter, throttle body, accelerator pedal position sensor, wiring defects, poor connections, software errors, hardware faults etc.
Any or a combination of these faults could cause the problem you have.
It is a shame that I have paid £13 for someone to state the obvious. I was expecting information such as disconnect the positive battery lead and reconnect. The ignition on, leave on, turn off repeat x times etc ....... plus a number of other things that could overcome the problem. Obviously I will not provide any detail of things that can be done as I am not being paid as an expert. Having been in the engine tuning and building business for over 30 years I though I would use this service to confirm information my friends have had which was equally not useful. Please do not contact me again.