MAP sensor part #

M

MR_MNZTR_SY

New member
i got one yesterday (YAY) and i just had a friend pick it up for me because he gets an employee discount. i forgot to tell him to get the 3 bar but i have a basically stock set up anyway so no biggie. the 2 bar part number listed at www.syty.org doesnt come up at www.gmpartsdirect.com but the 3 bar does. sooo for shits and giggles i decided to see which mine was and it was NEITHER! im assuming its the 2 bar and this is the new part number: 16254539.

um, thats if anyones really even interested i guess. heh. :drinking:
 
leroy

leroy

Donating Member
GM makes a 1 bar sensor also....not sure about the part number. They look identical for the most part.

Jim
 
Q

QUIKSUV

New member
1625439 is the new GM part number for a 2-bar sensor.

Do not use a 3-bar sensor without a 3-bar chip. 3-bar sensor with stock chip is BAD.

1-bar, 2-bar and 3-bar MAP sensors each have a different keying. Can't plug a 3-bar sensor in unless you carve out the key.
 
leroy

leroy

Donating Member
Good info Quiksuv. I've done a few 2 to 3 bar conversions and don't remember having to alter the key. Maybe that's something with the new part numbers, or it could be another senior moment.

Jim
 
ed hess

ed hess

race or get outta the way
wait a minute i have the 3 bar sensor and it plugs into the mount just fine.
what gives?
ed

Maybe its not a 3 bar even though it came in the correct box?
But the truck runs fine after the initial cold stall problem passes. ie
restart it 3 times.

anybody?
 
Q

QUIKSUV

New member
I was not talking about the mount but the Packard connector. The 3-way connectors have a different keyway for each sensor. I am pretty sure about this but I am on the road and can't run to the garage to check.

In the old days it was easy because the insert and connector color matched.

Green = 1 bar
Orange = 2 bar
Red = 3 bar

All are 3-way connectors but each had a different key. Maybe someone else can verify this by looking at a 2 and 3 bar sensor
 
M

MR_MNZTR_SY

New member
yeah, mine has a black connector haha. and what about the 3 BAR chip. i made a half attempt at asking about that a little while ago and was told no other mods were necessary but i knew i had read something about a chip. i really dont want to beat a dead horse here and its really inconsequential for me now that i have the new sensor but if some can just shoot me a quick answer id be happy.
 
Q

QUIKSUV

New member
THe part number you listed is a 2-bar sensor. Proper replacement for a stock truck.

Use only 3-bar chip with a 3-bar sensor.
 
M

MR_MNZTR_SY

New member
yeah i know. i just wanted to know what the 3 bar chip was all about. buuut if the bar in map sensor means BAR the unit of pressure measurement (and im gonna asume it does) then that means that you can get the 2 bar sensor to read up to about 30 psi because one bar is equal to 14.7 (i think) psi, so what would be the point of even switching to a 3 bar?
 
Q

QUIKSUV

New member
MAP means Manifold Absolute Pressure.

The sensor is an absolute sensor, not gage. So atmospheric pressure is about 15 psi, not 0. Therefore a 2-bar sensor is good to about 15 psi boost, a 3-bar can go to 30 psi boost.

Some guys want to run more than 15 psi so a 3-bar sensor and CALIBRATION must be used to get proper engine/boost control.
 
JSM

JSM

Active member
BAR is metric equivalent of pressure.

BAR is short for barometric pressure... the typical barometric pressure is 14.7 psi.

We all live in a world of 14.7 PSI, unless you start flying up in sky, then it drops off. Just think off all the air above you pushing down. Just like when you dive, the deaper you get the bigger the pressure.

14.7 is atomosphere, aka 1bar, 14.7 more (boost) is 2 bar, ~30psi, is 3 bar..

you need chip and map to MATCH... this has been discussed to death, I think jesus was in on the first discussion on this
 
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