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13

MAP = Manifold absolute pressure and is a sensor to measure vacuum, the computer calculates the engine air flow based on the vacuum, throttle position, and intake air temperature. The computer also measures the barometric pressure using the MAP sensor before the engine cranks, this lets the computer compensate for altitude, or how dense the air is. Typical ...


9

When I looked online, here's what I found about the location of the MAP sensor in your car. As always, a picture is worth a thousand words: From looking at other info about that car it's port injected, not throttle body injected (individual injectors on each cylinder, not just one on the throttle body). As far as I know there should never be fuel in that ...


5

Moves.. answer is a good one but you asked about advantages/disadvantages of MAF sensors. Disadvantages are: the sensor sits in the intake and thus restricts airflow. Airflow restrictions translate to performance restriction, particularly with vane style air flow meters. A simple example of this is the comparison between a Subaru STI MAF sensor and a ...


4

If the location shown in your profile is accurate, ambient pressure should be around 29.7 in Hg, so your neighbor's car seems to reflect the correct altitude. As @barbecue mentions, Wolfram|Alpha shows that 29.2 in Hg reflects an altitude of 205 m (674 ft) above sea level. If you compare the air densities resulting from these two readings, the percentage ...


3

In the turbo applications I am familiar with, both a wire or film (better) type MAF is used, in conjunction with a MAP, IAT, ECT, etc. Specifically on turbosupercharged Subarus, there's knowledge to be gained by also knowing intake pressure. Ultimately, you are trying to reach the best AFR. Things change a bit when supercharging, whether mechanical or ...


3

If the Barometric sensor (BARO) is incorrect will the fuel mileage will be affected? It depends, and only rarely . In control systems that use MAF sensors such your Azera the BARO is not needed except as backup to the MAF sensor. The MAF sensor measures the mass of the air entering the engine which is used by the PCM to decide how much fuel to mix with it ...


2

TLDR; Find a new shop to go-to as that one isn't doing anything for you besides taking your money. Also, get a service manual for your car if you want to be able to verify that troubleshooting is being done or get involved in a knowledgeable discussion with a mechanic/technician. (i.e. mechanic tells you the MAP sensor is bad, you ask for him to show you how ...


2

A small portion of exhaust gas is sent back to the intake to improve emissions via the EGR hose. If your vehicle is running rich, some fuel will be left unburnt in the exhaust gases. This can explain the wet fuel that you are seeing on the MAP sensor. Unfortunately, this is an indication of bigger engine operability problems. It doesn't surprise me that ...


2

In most vehicles you can find the Manifold Absolute Pressure sensor in the intake manifold. It is the same case with your vehicle. Follow the black tube from the front of the engine and you will see the sensor.


1

Finally solved! As I watched live readings on the scanner it showed that as soon as the ECM started getting info from the o2 sensor, going into closed loop, the engine would run bad until coolant temp. was 130*F or hotter. I replaced the o2 sensor, coolant temp. sensor and the thermostat for good measure. IT RAN FINE! I then replaced the ECT sensor with the ...


1

Pretty vague question, so this is a pretty vague answer. Having gotten wet, there could be nearly anything wrong. You are going to have to go thru the entire navigation system, component by component, to find the failure. Not knowing the extent of the water damage makes it impossible for us to know where to start. If the storm was strong enough to blow ...


1

Calculating Boost from OBD PIDs is pretty straight forward. Mode 01 PID 0B (Intake manifold absolute pressure) - Mode 01 PID 33 (Absolute Barometric Pressure) 255 doesn't sound like much resolution but it corresponds to 0-36.98psi. Which is a resolution of 0.145PSI. Another option would be to monitor the raw CAN bus data. Hook up a pot to the MAP sensor ...


1

The problem was the harness. On this car, there is a short "injector harness" which drives the injectors and the MAP, and is separable from the main engine harness. A solder joint near the MAP sensor connector was flexing and causing an intermittent signal path. I had another injector harness with an incorrect MAP connector, so I cut the connector off of ...


1

Atmospheric pressure changes are rarely fast enough to see them happen on a gauge, it tends to take minutes or hours for them to be noticeable. Unless you're experiencing strong weather or rapidly changing elevation, you probably would not see any change at all, so that part doesn't surprise me. Also, the sensors themselves are unlikely to be all that ...


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