Map sensor

[slow96stroke]

I have heard that there is something that you can do to the MAP sensor on the OBS trucks that is like installing a Boost Fooler. Does anyome know what I am talking about? Apparently another some resistor deal? I dunno.... Thanks in advance yall

[alabamafrog]

Resistor is bad, it will affect things at all times not just when over boosting. A 4.7 volt Zener diode will only affect it during high boost levels and costs about $1.

Just as for clarity, the Zener mod is just a map fooler. If you run high boost and have trouble with defueling and over boost codes then you may need a map fooler. You can buy a 4.7 volt Zener for around $1 and install in minutes. The factory map sensor is just a pressure sensor with a 0-5 volt output that goes back to the computer. By installing the 4.7 Zener you make the computer see the same voltage as before from 0-4.7 but stick at 4.7 as your boost goes higher, thereby fooling the computer into thinking you are running normal boost and preventing it from defueling. Many folks do this the mechanical way by installing blow off valves or pressure regulators in the map sensor hose. The 4.7v Zener is just a clean, cheap, electrical way of doing the same thing. To hook it you simple splice the banded end of the diode to the LG/BK wire and the other end of the diode to the GY/R wire at the map sensor. There is not really anything to take a picture of, it is so small and insignificant looking.

Here is an old post on it Did the 4.7 diode boost fooler

[97jdpowersmoke]

yea i pulled the plug and the hose off my sensor and duct taped the plug and clamped the hose to keep dirt out my truck was stock and i noticed maybe a 30-40 hp increase and more smoke when i floored it today i got my buddys super chip and plugged the map back in to do the diagnostics on it because unplugging it does throw a code or 2:fawkdance: (check engine light is on) the truck diddnt smoke a bit even on extreme performance tune then i unplugged the map again and it smokes every time i lean into it good i can roll smoke in every gear and not bad egt's even with stock exhaust

[CHUCK]

Wheres the MAP sensor located?

[slow96stroke]

pass side by the firewall....It is a little box, 3 wires hooked up in a harness and a hose going to it.

[97jdpowersmoke]

Originally Posted by CHUCK

Wheres the MAP sensor located?

this is a 00' but its in the same place on a 94-97 the plug is flat not square
ive had mine off over a week and no probs and enjoy the smoke unlike the little cars and durasux:fawkdance: behind me

[CHUCK]

thanks for the clairification and pic

[CHUCK]

ZENER DIODE 4.7 V/0.5 WATTS 4.7 Volt 500 mw 5% Zener Diode 4.7 Volt 1 Watt Zener Diode... which one would be correct? i have no clue of whats what

[masami]

The zener diode only works on the SD trucks since the SD map sensor has a voltage output. The OBS map sensor has a frequency output so the resistor will not work. The OBS map fooler is a pressure regulator or pop off valve that limits the pressure that the map sensor sees (about 22 or so psi).

If yo disconnect the map sensor on an OBS truck and the truck runs better, that means your map sensor is defective and should be replaced. Unplugging the map sensor makes the PCM revert to a default condition as far as map sensor input is concerned. A working map sensor will make the engine run better than the default condition will as it is responding to actual operating conditions.

There is a resistor mod for the OBS ICP sensor that increases the HPO pressure (10K mod) and generally will increase low end torque.

[al shapiro]

Would a potensiometer work on a super duty map sensor to change the voltage signal going to the computer so I can lean the engine out? I want to run a HHO (hydrogen generator) because of the price of fuel and they say that you have to lean out the engine to compensate for the HHO. Any help would be appreciated.