Peugeot 406 MAP sensor

Can anyone give me any advice on how to go about changing the MAP sensor
on my 1998cc Peugeot 406 coupe?

I have had an engine "juddering" issue that has gradually got worse and
eventually activated the engine warning light. I had the engine
management unit decoded and it said "254 - MAP sensor". A "10 mixture
error" was also reported that the man in the garage said often
accompanied a MAP sensor failure. I was also told that MAP sensor
failures were quite common on 406s.

My Haynes manual says that the MAP sensor is mounted on the inlet
manifold and removal/replacement is described in just 3 sentences.
Should be easy - eh?

I just can't see how to get to the sensor without either having an arm
with six joints or to remove the exhaust manifold to get at all the
bits underneath. In any case, I don't think that I can see the sensor.
Is there some easy way to change the sensor that I haven't spotted?

Many thanks if anyone who has solved this problem can reply.

Mike H.

 

Here is a follow up on the manifold absolute pressure sensor (MAP sensor) for those interested.

I have changed the MAP sensor. It turned out to be much easier than I thought. I will reply to your
questions and copy the newsgroup so that others may benefit. Remember my experience is for the
1998cc engine.

Firstly, the sensor cost £35.18 + VAT. I actually got it from my local Peugeot dealer after GSF said
that they didn't have one. I wanted it pretty urgently as although my car had its intermittant
juddering problem for some weeks, it had recently got worse and the engine warning light had come on
a couple of times allowing the cause to be logged in the engine management computer.

The MAP sensor is mounted on the RHS of the plastic inlet manifold quite low down. There is a single
10mm bolt (with washer) that bolt the sensor to the manifold. My concern was based on the fact that
the only way that I could see to get a spanner on it was from the top/side. This turned out to be
wrong and the best way is from the bottom, viewing from a hole at the top.

You need good daylight since when you start placing your hand over the gaps in the manifold it is
quite dark. I also used a spanner with total length about 6". I found that a shorter spanner would
not allow me to hold the end and keep the spanner true. A longer spanner got fouled on the
surrounding engine parts. Coming from under the manifold with my hand , but looking from a hole at
the top/side by the throttle housing, I undid the bolt by about 3 turns. It was then finger tight
and I could undo it fully by hand - taking care not to drop the bolt. The MAP sensor was held in by
what looks like a hose-lock joint but without the ratchet lock. I just pulled the sensor out and
pulled it under the manifold with the lead attached. I then replaced the sensor, fed it back up
behind the manifold, and inserted the end that looked like a pipe into the hole. By hand I could
place the bolt throught the mounting hole in the sensor housing, align the sensor so that ithe bolt
mated with the bolthole, and hand tighten the bolt. The final act was to tighten the bolt with the
ring spanner - taking care not to overtighten it in the plastic manifold.

I took the car out for a prolonged test-drive and it was perfect.

 

I have changed the MAP sensor. It turned out to be much easier than I
thought. I will reply to your questions and copy the newsgroup so that
others may benefit. Remember my experience is for the 1998cc engine.

Firstly, the sensor cost £35.18 + VAT. I actually got it from my local
Peugeot dealer after GSF said that they didn't have one. I wanted it
pretty urgently as although my car had its intermittant juddering
problem for some weeks, it had recently got worse and the engine
warning light had come on a couple of times allowing the cause to be
logged in the engine management computer.

The MAP sensor is mounted on the RHS of the plastic inlet manifold
quite low down. There is a single 10mm bolt (with washer) that bolt
the sensor to the manifold. My concern was based on the fact that the
only way that I could see to get a spanner on it was from the
top/side. This turned out to be wrong and the best way is from the
bottom, viewing from a hole at the top.

You need good daylight since when you start placing your hand over the
gaps in the manifold it is quite dark. I also used a spanner with
total length about 6". I found that a shorter spanner would not allow
me to hold the end and keep the spanner true. A longer spanner got
fouled on the surrounding engine parts. Coming from under the manifold
with my hand , but looking from a hole at the top/side by the throttle
housing, I undid the bolt by about 3 turns. It was then finger tight
and I could undo it fully by hand - taking care not to drop the bolt.
The MAP sensor was held in by what looks like a hose-lock joint but
without the ratchet lock. I just pulled the sensor out and pulled it
under the manifold with the lead attached. I then replaced the sensor,
fed it back up behind the manifold, and inserted the end that looked
like a pipe into the hole. By hand I could place the bolt throught the
mounting hole in the sensor housing, align the sensor so that ithe
bolt mated with the bolthole, and hand tighten the bolt. The final act
was to tighten the bolt with the ring spanner - taking care not to
overtighten it in the plastic manifold.

I took the car out for a prolonged test-drive and it was perfect.

I hope that this helps you. If not then drop me an email...