ECU Fault codes. What do they mean?
 

Firstly car is a 1995 Classic Turbo Wagon

Got a check engine light last Saturday on way to a rugby game, phoned dealer who told me to check oil and water and if they were ok then continue driving.

So today I checked the fault codes which came back as

32) A/F Sensor #1 or #2 system.
42) Idle switch.

Now when I bought the car it had too high a hot idle so I flagged this up and was told it would be fixed as part of the sale so I would assume this will be fixed.

Code 32 (A/F Sensor #1 or #2 system) not sure what this is and whether or not it will be covered under my Scotsure dealer care 3 warranty.

Any thoughts,

Robert.

Codes 42 and 32
 

Some cars have 2 oxygen (lambda) sensors in the exhaust whilst others have only one (this is usually in down-pipe immediately after turbo). So code 32 is also given as just 'oxygen sensor'. A dodgy oxygen sensor often results in an erratic idle, as this sensors measures the level of oxygen in the exhaust gases and the ECU then alters fuelling/ignition to keep the oxygen level at the desired value as specified in the ECU. Under acceleration the output of the oxygen sensor is ignored by the ECU.
Code 42 is given as idle switch and refers to the idle switch signal generated by the throttle position sensor. When the throttle is closed the throttle position sensor outputs the idle switch signal to the ECU. The idle control valve circuit will then operate to maintain a steady idle speed.
So both errors you have may be directly related to an uneven idle. Oxygen sensor error 32 sometimes occurs when another component is not functioning correctly and the oxygen sensor itself is OK, but if this sensor has not been replaced in the last 3 years then I'd be inclined to replace it anyway, get the ECU reset and worry about error 42 (and the throttle position sensor) if it returns.
Kevin