P0170 Fuel Trim Malfunction (Bank 1)

[j76c]

Hi All,

I hope you can help the car is a Peugeot (2001) 206 CC 2.0 which I have owned now for three years and keep well maintained. Apologies if this is a bit of a long message but wanted to ensure you have the full brief.
Engine Management light came on and stayed on last night. had a idle splutter whilst waiting at lights when this occurred. Put the code reader on and it came up with :

P0170 Fuel Trim Malfunction (Bank 1)

Search the internet and it mentions the MAF sensor (Master Air flow sensor) and to clean/replace.
Attempted to search for this part and cannot see the part number for this model year and engine size?
I can see that there is a MAP sensor is it used instead of a MAF in this model?

If anyone knows the part number or any knowledge I will be very grateful thank you

[Capncol]

Hi and welcome. It's nice to be given such a full description of problem.

I would start by checking for any vacuum leaks in the plastic pipework for the inlet manifold, brake servo pipe etc: It is common for these to crack when they become brittle and this will cause the engine to run lean. Next is to take throttle body off and give it a good clean with carb cleaner or brake parts cleaner. With age, the "throttle plate" and inlet throat get gummed up with a sticky carbon residue which can cause the butterfly to stick a bit, specialy at idle where it is nearly closed. Try this and let us know what you find.

[j76c]

Thank you for such quick reply I shall indeed feed back findings

[j76c]

check for any vacuum leaks in the plastic pipework for the inlet manifold - all good
brake servo pipe cracks they become brittle - very true statement when I replaced the coil pack six months ago saw it had been taped up removed tape and had two clean brakes so replaced
take throttle body off and give it a good clean with carb cleaner or brake parts cleaner. With age, the "throttle plate" and inlet throat get gummed up with a sticky carbon residue which can cause the butterfly to stick a bit, specialy at idle where it is nearly closed - exactly how you described cleaned up lovely with brake cleaner. Was now able to clear engine light with reader and idles with a lovely low even hum . Just took her for a ten mile run and very smooth!

Thank you so much for your help 5* fault diagnosis!

[Capncol]

A pleasure

[GrandadMonkey]

One of the reasons I will only use Shell V-Power Nitro+ and BP Ultimate petrol in our 206cc

http://www.shell.co.uk/gbr/products-ser ... eaded.html

http://www.bp.com/en_gb/on-the-road/uni ... eaded.html