How to increase idle speed on peugeot 405 sti

what country sold? lots of 405s' world wide and diffr.
engine performance ?(on an engine stand?)
or the driving wheels to road performance.?
please say exactly what you want or post symptoms. or?
engine codes are very hard to find here. (USA)
ah, but are here.
http://www.scribd.com/doc/25423642/Peugeot-Engine-Code-Reference-List
XU5 or XU9 something are the engine, codes.

wiki: ,see bold , I added.
The 405 was available as a 4-door only. Four-cylinder petrol engines included 65, 92, 110, 125, and 160 hp (48, 69, 82, 93, and 119 kW) units. A 1.8-litre diesel engine, with or without a turbo (70 and 90 hp (52 and 67 kW)) was added to the range during 1988 as was the 5-door estate.
the 405 ended in USA in 1991.
The 405 range included three petrol engines and two diesel engines, all four-cylinder with no 6-cylinder option, in a variety of states of tune and specification. The range was tailored to suit different export markets. The 1.6-litre saloon featured a low drag co-efficient of Cd=0.29, with other models varying up to Cd=0.33. The 1.4-litre (1,360 cc) engine was fitted with a four-speed manual gearbox. It produced 70 hp (52 kW) at 5600 rpm. The 1.6-litre (1,580 cc) engine was fitted with a five-speed manual gearbox and produced 92 hp (69 kW) at 6000 rpm. The 1.9-litre (1,905 cc) engine was available with a five speed manual gearbox, with an option of an automatic in the lower powered version.
The 8-valve version of the engine was available in two levels of tune; 110 hp (82 kW) or 125 hp (93 kW). A 16-valve version was available with the Mi16 model and this produced 160 hp (120 kW) at 6500 rpm and could reach a top speed of 220 km/h.[4]

Sounds like a faulty idle air control valve.
The computer controls idle speed by regulating how much air enters the intake thru the valve.
Could also have gum-sludge in the throttle body.

did you know that peugeot made the shittyest transmissions ever but any who take it to a car parts store and have them test it for free.

change the appropiate coil pack thats all

Do you have a check engine light on? First thing I would do is unplug the IAC motor when the engine is warm. If the idle speed doesn't change you have a vacuum leak or a bad IAC motor. If the idle speed goes down you might have a bad TPS or IAC

Manual 2 litres
Auto 4 litres

Its a dpf not a cat.Easy way to clean out[regenerate]First bring the engine to normal temp bring up the rpm to 4000 for 2 mins,then allow to idle for 30 seconds then bring the rpm up to 3000 rpm for 3 mins and yourfilter will have regenerated [fancy word for clean itself out. DPF = diesel particulate filter.Its important to use good quality low ash oil for your oil changes.

remove and clean idle speed control valve
if that doesnt cure it replace the idle speed control valve

Hi djay,
the idle speed control can be adjusted on the pump by turning the adjusting screw that stops the accelerator lever.
Cheers

That is normal. When you put it in gear, the idle speed drops about 400 rpm.