Sometimes my truck feels like its got about 350 rwhp, and other times maybe 50 rwhp, maybe. I kinda assumed it was the wires going into the VC to the injectors, but then I started playing with the EOT mod in my free time. It wasn't working properly, so I checked for codes. One code: P0236, Turbo Boost Sensor A circut malfunction or something along those lines. That code has never been there before and this power issue has been happening for awhile now, and it is getting more common. Since I wasn't messing anything directly related to that code I completely took out the EOT mod. So I decided to unplug the MAP and go for a drive around the block. I unplugged it and the CEL came on. It had never done that before. Checked the code: P0237. Something about the sensor, which i figured was becuase I unplugged it. Went for the drive around the block. The dang thing ran great, which is contrary to what I had expected.

So my question is: When I unplug the MAP, if the sensor was working properly I would be down on power and if it was faulty then I would not notice a difference, right?

The thing that has me confused is when I unplugged the MAP, the truck actually had all the power that it had when it felt like 350 horses with it still plugged in. And furthermore, it did not do the whole 50 horsepower thing.

Sorry for the long post, but I need help.

 

I believe, when you unplugged the MAP plug, the computer went into closed loop run. A preset values stored in the computer and not relying on any sensor input. when you plug it back in, the computer reads the values from the sensor which is giving bad info, so the computer sets everything else accordingly. Sounds to be a bad sensor.

 

Phil, unplugging the MAP allows the PCM to make a best guess on Boost using other sensors. If unplugging the MAP results in better performance then you either have a bad MAP sensor or clogged MAP hose. Since the MAP sensor seldom fails (costly too) I would check the hose that goes from the MAP sensor to the intake (passenger side) for quality (cracks) and clogs. Just take it off and blow in one end.

 

Well I drove the old girl a little more with the sensor unplugged, and to update the info above. It has more power now than when the sensor is plugged in and 'working properly' I may not even get a new one.

 

po236 sets for less than 13 psi boost being seen by the map snsr.
i have 11 psi with code and cant figure it out. with my ts chip on max my boost goes to 17 psi- that tells me its not leaking boost- just not fueling properly!!! i think the chip only changes injection timing and pressure? this is where i need a ps guru please!!!!

 

the chip, if im thinking right, changes pressure, timing, the longevity of the injectors delivering fuel, oil pressure and trans fluid pressure. my truck only seen 17 before a chip now i see 25 to 27

 

all the diagnostics are telling me to replace my turbo or computer! if it were a boost leak, would i still be around 11 psi with chip on max?