This is in relation to the other thread about the misfire on my Polo 9N 2005.

I've just got back from the mechanics as I've recently changed the plugs, coils and Injectors and wanted the ECU cleared as I thought this may cure the misfire and they came back with code 17961 Barometric/manifold pressure signal.

I asked him what it meant and he had no idea.

No codes about misfires strangely enough.

It had a bit of a misfire before but as I tried to drive it out it had literally lost all acceleration. God knows what's happened, its gone from being a bit ropey to totally undrivable.

The MAP sensor is on the cambelt end of the inlet manifold, they do get gummed up with oil deposits, when it gives poor signals it normally puts the EPC light on not the EML so I'd remove it (two torx screws) don't loose the "O"ring !! then spray it with carb cleaner, don't use any brushes as it's easy to damage,

Thanks once again Nige8021!

I will have a look to see if I can resolve it.

I am at the end of my tether with this problem, I am on Autotrader as we speak looking for a new car.

While I was poking around under the bonnet I noticed that a pipe leading away from the throttle body into the driver's side of the cabin looked damaged where it met the TB.

Is this significant in any way?! I have a can of carb cleaner on the way to help me clean the MAP sensor, its top of the list.

If that pipe is split it could be giving an unmetered air leak which could also contribute to that fault code, can't think what pipe would be leading into the cabin though??

Maybe not into the cabin but towards a part of the engine that is directly behind the steering wheel. You'll have to excuse my ignorance, I still know sod all about these things.

It might be running around to the carbon canister valve by the drivers side suspension strut top.

I thought in your other post we had asked you to check all the vacuum pipes coming from the inlet manifold/throttle body ?? or it might of been post ??

I don't remember anything about vacuum pipes as so far I've been focusing on other areas. At least it gives me something to work on though as I keep drawing blanks.

Is it worthwhile just replacing the MAP sensor? My only concern is that I'm giving the ECU a bit too much in one go.

Edited 29 September, 201510 yr by Chefdave

I would try a clean first, as that code isn't a direct link to the sensor,( if it was a MAP sensor range error or something similar then a replacement might be the best way) it's just listed as a possible cause for that code, other possible ones include vacuum leaks! I didn't flag it up earlier, as I said, I thought we had asked about the vacuum pipes in your other post

Perhaps if I spray a bit of water around the suspect pipe that will help with the diagnosis?

I'm just sitting through a comprehensive 40 minute Youtube video on MAP sensors by Schrodinger's Box, at least I know a little bit more now!

Thanks once again.

Water won't do anything, if you spray the carb cleaner at the pipe(shield the throttle body intake) and the rpm fluctuates you definitely have a split pipe