Antipollution Fault

[adrjoh]

Hey,
Hoping someone can shed some light on a fault for me.

I have a 406 2.0 Hdi 90, which was running pretty sluggish when pulling away.

I disconnected the maf, which seemed to make her a bit sharper, so I sprayed the maf with maf cleaner, and replaced.

Ever since doing this, upon braking, an antipollution fault is triggered, which pops the engine management light on, which then will go off and clear as soon as I pull off again!

5 days till MOT time, so really hoping it's fairly easy to resolve!

Any advice very much appreciated!

[rwb]

"Anti polution" is a generic message that is shown for dozens of different and unrelated underlying problems.

When you brake? Or when you take your foot off the accelerator? I know one of the many conditions under which "anti polution" is shown is when you've taken up slightly too much slack in the throttle cable.

I can't remember what the logic is with unplugging the MAF. I'd expect that unplugged = anti polution, EML, and limp mode.

[GingerMagic]

The MAF is unplugged to determine the reason for sluggish performance at lower revs, sometimes it's improved, sometimes not...
The braking and EML light is confusing me - I'm trying to figure out in my mind what the Hdi90 has that could lead to this - the vacuum system is basic so I don't think it's the servo....
How about a dodgy EGR which is feeding the new clean MAF the wrong amount of airflow..?

[adrjoh]

Thanks, will pop some EGR cleaner through it and have a play with the throttle cable also, I had adjusted it but the fault appeared a couple of days later.

[adrjoh]

Just released the throttle cable clip by 1 and taken it for a drive and no warnings! Must have been that!

Thanks for your help!!

[GingerMagic]

Good result, and a nice easy fix

[WillNZ]

I can't remember what the logic is with unplugging the MAF. I'd expect that unplugged = anti polution, EML, and limp mode.

Unplugging the MAF activates a generic map in the ECU which allows the car to be driven, albeit less economically, as it assumes air intake based on rpm etc. It is normally used to determine if the MAF is faulty if the engine runs smoothly after unplugging the MAF. It will not normally switch on the antipollution or put the vehicle in limp mode. I know of people who have driven their 406's for years with no MAF.