MAP (Mass Air Pressure) please help me

[mustafa76]

Hi for all of you

my car vt 1999

I disconnected both MAP(Mass Air Pressure) and MAT(Mass Air Temp Sensor) and no check engine light on the dash !!!, is that normal?

[showbags]

yes, this can be quite common. i had a faulty mass air flow sensor which would not set any codes. makes it very difficult to diagnos problems.

[Sabbath']

Are you talking about your MAF sensor? (Mass Air Flow)

[WogBoyz]

i though the vt only had a MAF?

[ahmedomnnea]

my vx has both MAF and MAP, I don't know why.

[undar8ed1]

Yes they do have both, thats why when you get a MAFLESS tune on an LS1 it (PCM) relies solely on the MAP sensor readings in the manifold which inturn gives better throttle reponse. go figure.

[mustafa76]

thanks for your replay

most of you did not answer my Q
yes i have the 2 sensors .
but i am talking about disconnecting them . is that make the check engine light to come on the dash?or not

[sleepa]

Will it even run with those disconnected?

[mustafa76]

yes it is run with those disconnected

[Vt_vic]

yes it would run prolly rough and would use more fuel

[mustafa76]

i do not have any check engine light on the dash. but my car now run prolly rough and use more fuel even with these sensors are connected but when i disconnect these sensors no check engine light on the dash !!!, is that mean that these sensor are bad or what??

[V8Silverfox]

i do not have any check engine light on the dash. but my car now run prolly rough and use more fuel even with these sensors are connected but when i disconnect these sensors no check engine light on the dash !!!, is that mean that these sensor are bad or what??

I would think that if your car is running very rough with the sensors disconnected then it's a good indication that they are working.

[mustafa76]

th for your replay

the car is the same when connected or disconnected
it is lose the performance when the car reach to normal heat

[showbags]

each vehicle is different. some ecotec's run rough with them disconnected others don't. if your losing power when it heats up your MAF sensor(air flow meter) is cactus. second hand one will cost you about $30 from the wreckers or you can pay 400+ from gmh.

[ari666]

call me stupid, but MAP stands for manifold actual pressure... well at least it does on turbo cars anyway... carry on.

edit* wtf is a MAT sensor??? does that even exist? my guess is that your disconnecting plugs at random and you shouldnt be.

MAF stands for mass air flow btw

[mustafa76]

i replace maf sensor with new one but the problem is still there .
when i disconnect maf sensor the check engine light come on the dash
but when i disconnect map sensor there is no check engine light on the dash
computer test give me no error code

what is that ?

[ari666]

what problem? it sounds like you disconnected your MAF... tried plugging it back in?

[mustafa76]

what you are talking about?

ok ok i do not need any help for my problem.
just i want to know if i disconnect map sensor is that make the engine light come on the dash or not ?

[WogBoyz]

i replace maf sensor with new one but the problem is still there .
when i disconnect maf sensor the check engine light come on the dash
but when i disconnect map sensor there is no check engine light on the dash
computer test give me no error code

what is that ?

where is this map sensor located got any pics?

[Sabbath']

what you are talking about?

ok ok i do not need any help for my problem.
just i want to know if i disconnect map sensor is that make the engine light come on the dash or not ?

If you have your MAP and MAF sensor unplugged, the ECU is going to have no way to work out the fuel mixture, and at the least, illuminate a warning light.

[mustafa76]

this is the pic of mine i cant see any hose connected to map what is that

[undar8ed1]

The sensor you have classed as MAT is acctualy the IAT sensor Intake Air Temp sensor and would definatly throw a code up on the dash if disconnected or if faulty and connected same with the MAP as well, but yours is not throwing a code so I`d say your DTC (engine check light for those playing at home) light on the dash has a blown globe or fuse.

[mustafa76]

th for your replay

i am in saudi arabia i found that my car since it was new came that way from the dealer : no O2 sensors and the MAP sensor is not connected to the intake manifold (by a hose since the MAP sensor is far from the intake manifold).

when i disconnect both MAP and IAT there is no light on the dash

where can find these fuses in my car .

and th for all of you

[wana s' charge stock vt]

........if ya maP isn't connected by a vac hose and when ya disconnecting it it dont change anything or display engine check light its prob not even being used for anything. if ya disconnecting ya maF and it changes things and ya light comes up , its prob what ya car is running off (not the maP) from what i've been told ya car runs off maf or map. not both together. maf's factory- map's custom(from what i've been told)

as for the mat/air temp one- if i disconnect mine the engin light comes up.

also- wash ya bloody motor lol,

[ari666]

edit* wait...