The check emissions light can mean many things.
When the engine electronics sense a fault, a warning light is switched on and a 'trouble code' is stored in the memory. There used to be one 'engine management' light , but now there are different lights for the various sub-systems. Even if the fault is intermittent and the light goes out by itself the code(s) will be stored.
You need to take the car to a garage or diagnostic specialist to have the code(s) read. It doesn't have to be a Renault dealer.
A basic code read should not cost more than £40, a full diagnostic (which should include live-data testing of the various sensors and actuators) considerably more..
The codes will tell us what part is showing a fault, but does not necessarily mean the part is faulty! For example, a leaky exhaust can post up a lambda sensor code as the excess oxygen throws the sensor out of range. Replacing the sensor would obviously not solve the problem, but many 'technicians' will tell you the computer is infallible.
Anyway, lecture mode over!!
EGR is the Exhaust Gas Recirculating valve. As the name implies, it opens to allow some of the exhaust gas to be blown back into the manifold, helping to reduce emissions. They have a tendency to stick and choke, and can put the emissions light on. They can sometimes be cleaned but often have to be renewed.
Dont let the mechanic change things on a trial and error basis, it'll cost you a fortune.
Get the codes read and post the results up here, preferably in a new post.
jonnie09, May 2009
