Air pressure sensor?

[N13SCB]

I had posted up a question before relating to a P0299 fault code that my car is picking up. Last week I sent the car to a specialist to hopefully sort it, but it still hasnt happened.

Im getting told that my atmospheric readings are nearly four times higher than what they should be at idle, for whatever reason the mechanics told me this on the Wednesday and by Friday they hadnt changed a single thing and gave me the car back.

Iv been told there is a sensor that picks up these atmospheric and air pressure readings, was just wondering if anyone has had this kind of issue before. My car has a stage 1 map and is making less power than a standard gti and it doesnt feel lively at all to drive. Im hoping this is the cause of my drastc lack of power 

Thanks, Stu.

[bacillus]

Did they check the DV?
http://wiki.ross-tech.com/wiki/index.php/16683/P0299/000665

[N13SCB]

Sorry I should have said, the dv, n75, plugs and oil have all been changed. The MAFM has also been checked over and cleaned. All pipework has been pressure tested and leak tested. Compression has been checked as well. None of these changes have made any difference. I have plumbed in a boost gauge and the engine is making 16psi and very quickly with no leaks or spiking but to drive its feels like there is no boost at all!

Stu.

[bacillus]

I suspect in your case unless you actually log the car it will difficult to give a definite answer as to the cause.
Do you have a warning Check engine light in the dash?

[N13SCB]

That might have to be the next step, there have not been any warning lights at all. It is only showing when the car is plugged in to a diagnostic computer 

Stu.

[RS6BRIT]

I think the sensor your refering to is a MAP sensor (Manifold Absolute Pressure). most turbo charged cars run them, its how the car reads boost and Vac in the manifold then adjusts the N75 to the required duty cycle for the requested boost versus the actual boost.

Alot of people think that as our cars use a MAF sensor for fuelling that there isnt a MAP sensor, but as far as I'm aware this isnt the case.

What garage did you go to and what diagnostic equipment did they use ?  Map sensor readings can be very confusing as the read pressure needs to go through a calculation to take into account the fact that when at sea level there is already a pressure reading of 14.6psi, for example 0psi on your boost gauge would actually already be 14.6psi as that is what the standard air pressure at sea level is.

I once had a dashdaq, and when set to read boost it gave very confusing results as the boost gauge would show one reading and the dashdaq another. This was solved by an equation that had to be manually input to suit the standard air pressure in your region.

If the diagnostic equipment that was used by the garage gave ACTUAL readings it is quite possible that it would seem that they were miles out.

Its just a thought, not saying theres not a fault with it just want to check before you go pulling sensors that are not faulty.

[PDT]

Datalog block 115 with vagcom and pot the result. Also get a competent person to test the map sensor which is simple with the right tools and knowledge.