406 hesitates

My 2 litre 406 GTX auto has just started to idle rough. Its also lumpy at a
cruise speed, ie with little throttle. If I floor the pedal it clears until
i back off to cruise again. It will drive like that for about a mile then
that nice little engine light comes on in the dash and it runs smooth.
Any clues? Mal

 

It sounds like something connected with the fuel injectors and or it's
management system. If it is it will be costly and unfortunately usually can
only be dealt with by Pug specialists. Peugeot one day will build good
petrol engines, but that day has yet to come. When mine played up it cost
over £200+ that's for a V6 though. It was mainly labour. A good full day.

 

it sounds like the egr valve is not operating correctly needs diag 2000
diagnosis at pug dealer to confirm

 

Hi, There should be a fault code entered into the ECU following the
engine light illumination, so a read of the codes should give you a
start.
However the list is long of all the possible cures. The first reply
from Peugeot dealers will probably be to replace the coils assy ,
whether it needs it or not, and if they do it iwill set you back £220
for parts and labour!

If you fancy DIY the following list is taken from the link below

Cuts out
Misses:-
Check Secondary Ignition System
Check Fuel Pressure
Check IAC Motor Operation
Check The Minimum Idle Air Flow
Check EGR System
Check For Oxygen Sensor Switching
Check PCM Power And Ground Circuits

Hesitation:-
Check Secondary Ignition System
Check Engine Vacuum
Check Fuel Pressure
Check ECT Sensor Calibration
Check TPS Calibration
Check MAP Sensor Calibration
Check IAT Sensor
Check IAC Motor Operation
Check The Minimum Idle Air Flow
Check EVAP Emission System
Check EGR System
Check For Oxygen Sensor Switching
Check O2 Sensor Heater
Check PNP Switch
Check PCM Power And Ground Circuits

Most results seem to be got from changing coils and cleaning/replacing
IAC motor (idle control valve)


http://autorepair.about.com/cs/faqs/l/aa042603a_1.htm

T