I recently used a gunsons unit to flash the fault code from my PUG 306 2.0 XSi 1997 reg. Basically it stalls when starting from cold. I thought it was something to do with lambda sensor. The gunsons unit gave me code 52 which in it's code book means the car has a fault with the Lambda system control. Now is this something I can fix myself? I.e. put in a new lambda sensor or lambda system control or is this a garage job? I'm pretty handy with the car, not the best but I can muddle through. The Haynes manual I've got isn't much use with this problem.