A friend has a petrol peugeot 307 about 3 year old.
  The engine warning light has appeared on the dashboard display
along with a message reading "anti pollution fault "
 They can drive the car ok and the performance seems normal but can anyone 
tell me what can be causing the fault lights ?

"tomm"  gurgled happily, sounding much like
they were saying:

> but can anyone tell me what can be causing the fault lights ?

The fault codes can. Anything else'd be a guess.

"tomm"  wrote in message 
news:004b218e$0$22180$c3e8da3@news.astraweb.com...
>A friend has a petrol peugeot 307 about 3 year old.
>  The engine warning light has appeared on the dashboard display
> along with a message reading "anti pollution fault "
> They can drive the car ok and the performance seems normal but can anyone 
> tell me what can be causing the fault lights ?

Yes, it's the MAF sensor which is in the pipe going from the air filter 
housing to the engine.
Never rely on fault codes from the computer as they can be misleading to 
unqualified
mechanics who only know to look the code up in a book.  Experience is what 
counts and
identifying the cause of the error code.  The exhaust emissions light can 
come on if the mass
air flow meter is knackered because the engine can't tell how much air and 
fuel to mix.  It
ends up pushing more petrol or diesel in than required.  The sensors in the 
exhaust side sense
this and report a fault.  As it gets worse the performance will die off or 
acceleration will
be nowhere near as good.  At some point it will go in to an emergency mode 
and use up
quite a bit of petrol.
If it had something simple like a blackened air filter it would be obvious 
and would
probably not clear such a fault.  After 3 years the filter wouldn't be 
clogged up that much
anyway although it could look a bit irty due to the dust it filters.  The 
surface area is massive.

If you are going to have a go at fixing the car then I would look at a few 
hundred pounds.
That's what a new MAF sensor is for modern cars as you want a genuine one 
and not some
nasty copy.  The MAF only lasts about 3 or 4 years anyway - or at least they 
have in my cars.

On Sun, 27 Jul 2008 20:45:54 +0100, Paul P  wrote:

> "tomm"  wrote in message
> news:004b218e$0$22180$c3e8da3@news.astraweb.com...
>> A friend has a petrol peugeot 307 about 3 year old.
>>  The engine warning light has appeared on the dashboard display
>> along with a message reading "anti pollution fault "
>> They can drive the car ok and the performance seems normal but can  
>> anyone
>> tell me what can be causing the fault lights ?
>
> Yes, it's the MAF sensor which is in the pipe going from the air filter
> housing to the engine.

Well it's the most likely culprit, but it could also be either o2 sensor,  
either the sensor plugs, the cat, an air leak, an exhaust leak , a missing  
fuel filler cap etc. Getting the codes read will be cheaper than a MAF

> Never rely on fault codes from the computer as they can be misleading to
> unqualified
> mechanics who only know to look the code up in a book.  Experience is  
> what
> counts and
> identifying the cause of the error code.

Which is why most of them will /guess/ it's the MAF sensor

> The exhaust emissions light can
> come on if the mass
> air flow meter is knackered because the engine can't tell how much air  
> and
> fuel to mix.  It
> ends up pushing more petrol or diesel in than required.  The sensors in  
> the
> exhaust side sense
> this and report a fault.  As it gets worse the performance will die off  
> or
> acceleration will
> be nowhere near as good.  At some point it will go in to an emergency  
> mode
> and use up
> quite a bit of petrol.
> If it had something simple like a blackened air filter it would be  
> obvious
> and would
> probably not clear such a fault.  After 3 years the filter wouldn't be
> clogged up that much
> anyway although it could look a bit irty due to the dust it filters.  The
> surface area is massive.
>
> If you are going to have a go at fixing the car then I would look at a  
> few
> hundred pounds.
> That's what a new MAF sensor is for modern cars as you want a genuine one
> and not some
> nasty copy.  The MAF only lasts about 3 or 4 years anyway - or at least  
> they
> have in my cars.
>
>
>
>

On Sun, 27 Jul 2008 20:45:54 +0100, "Paul P"  wrote:

>
>"tomm"  wrote in message 
>news:004b218e$0$22180$c3e8da3@news.astraweb.com...
>>A friend has a petrol peugeot 307 about 3 year old.
>>  The engine warning light has appeared on the dashboard display
>> along with a message reading "anti pollution fault "
>> They can drive the car ok and the performance seems normal but can anyone 
>> tell me what can be causing the fault lights ?
>
>Yes, it's the MAF sensor which is in the pipe going from the air filter 
>housing to the engine.
>Never rely on fault codes from the computer as they can be misleading to 
>unqualified


Hmmm I would sooner rely on fault codes than your "expert" opinion.

IIRC you stated that "The piston probably has a hole in it." in the
thread "Running on 3" when the OP in that thread stated the
compressions were 150, 150, 142, 140 psi
-- 
Jimmy

"tomm"  wrote in message 
news:004b218e$0$22180$c3e8da3@news.astraweb.com...
>A friend has a petrol peugeot 307 about 3 year old.
>  The engine warning light has appeared on the dashboard display
> along with a message reading "anti pollution fault "
> They can drive the car ok and the performance seems normal but can anyone 
> tell me what can be causing the fault lights ?

Sorry, no.

I had an 02 plate 307 SW 2.0 petrol from new which randomly showed this 
message and had to be reset by the dealer/AA.

Twice it also went into limp home mode whilst showing the message - once on 
a French motorway. Never got to the bottom of the cause despite much 
interrogation and parts swapping by several Peugeot dealers and after 12 
months and 32,000 miles of aggro persuaded the company to send it back to 
Leaseplan.

Out of the five Peugeots we've owned this was the only one that gave any 
major problems. I pity the poor sods who bought it after!

"Jimmy"  wrote in message 
news:24or845lejgq58v36cked51bkaotg17ncf@4ax.com...
> On Sun, 27 Jul 2008 20:45:54 +0100, "Paul P"  
> wrote:
>
>>
>>"tomm"  wrote in message
>>news:004b218e$0$22180$c3e8da3@news.astraweb.com...
>>>A friend has a petrol peugeot 307 about 3 year old.
>>>  The engine warning light has appeared on the dashboard display
>>> along with a message reading "anti pollution fault "
>>> They can drive the car ok and the performance seems normal but can 
>>> anyone
>>> tell me what can be causing the fault lights ?
>>
>>Yes, it's the MAF sensor which is in the pipe going from the air 
>>filter
>>housing to the engine.
>>Never rely on fault codes from the computer as they can be 
>>misleading to
>>unqualified
>
>
> Hmmm I would sooner rely on fault codes than your "expert" opinion.

Especially as he hasn't even seen the car, never mind been told the 
fault code...!

>
> IIRC you stated that "The piston probably has a hole in it." in the
> thread "Running on 3" when the OP in that thread stated the
> compressions were 150, 150, 142, 140 psi

LOL, or should that be COL? :~(