Getting Error Code P1408       MDP Sensor circuit malfunction~ Manifold pressure differential

The three thing I found on line to check are:

Faulty MAP Sensor.

Censor harness open or shorted.

MAP sensor circuit poor electrical contact.

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Is there a why to check if the Sensor is bad?

Thanks

Getting this same fault.   Removed it, it's sooty but clean enough and passages aren't blocked.   My air filter is very dirty I wonder if that can have an effect?  Added a can of seafoam, going to drive a bit and monitor my map sensor, is it noticeable if the valve opens?

Anybody have a diagram so I can see which terminals to test?

Bandit - I might be mistaken, but I don't think you and sidekickyc are talking about the same thing - if you are, then you have a serious issue somewhere.

What you're describing there sounds more EGR related than MDP.

P1408, the Internet believes it is the EGR fault.  While monkeying around I noticed my car didn't have a MAP reading.  I went down to the local part source that has a scanner, had it read, no map reading.  p1408 is the map sensor.  Actually had 2 faults on that not just one. 

Back home I got the meter out.  Sensor gets a solid 5v, and a good ground.  Removed the map sensor and hooked up a vacuum, had to poke through the wires to get a reading, but again verified a 5 volts and ground, and an alternating 1-5 volts.  Signal.  Map sensor good.  Next I went to the ecu to see if signal arrives. The second plug from the left wasn't all the way in.  Seemed stiff.   I removed it only to find 4 or 5 pins twisted around and bent!!! After removing the ecu I straightened all the pins, plugged it back, so far no p1408 codes.   

The big challenge with the internet is deciding which source is credible and which is not.

Maybe a P1408 is an EGR related code on some make of car out there, but on a Suzuki, it has a very specific meaning - MANIFOLD DIFFERENTIAL PRESSURE CIRCUIT MALFUNCTION - the details are there in Sidekickyc's post - the only thing he has missed is the vacuum port that the sensor connects to.