1.0 mpi EGR valve problem?
 

I have a 2001 seat Ibiza with the 1.0 mpi engine. It has been suffering from a rough idleas though the engine were missing. I have had it plugged into a garage's diagnostic computer (Launch X431 is the platform) and they have reported a number of fault codes logged by the Ecu. They cleared the codes and took the car for a run. When they returned, the engine management light had reappeared and three new fault codes were recorded:
1)" EGR valve implausible signal..."(or roughly that)
2)"Random/multiple misfire
3) Misfire cylinder 1

From what I gauged from the mechanic, if the EGR valve is stuck open , the combustion mixture is being (for want of a better word) diluted by excess exhaust gases and may cause the misfire being signalled to ECU. Would it therefore be an idea to replace the EGR valve? What puzzled me however is the nature of the fault recorded. Has anybody known for the wiring between ECU and valve to be faulty hence the "implausible signal" or is it just that the solenoid may be broken, so the ECU cannot actuate it?

He aso mentioned that the throttle body may need to be reset to its basic setting, a function his equipment can perform. Would this be advisable?

Any help here would be GREATLY appreciated as a new valve is in the region of 180 euro, and I don't want to fork that out if it ends up being ECU. Thank you.[/align]