cannuck

Had the stage 1 installed. Got a great kick in 3rd and 4th the normal 21 to 23. Hitting it hard on the highway I lost all boost. Once the car restarted I only get 14 to 17 feels like stock.
I have the forge bypass say 4yrs. Checked the vacuum lines. I guess I could check the forge unit internally.

How do you know if the map sensor is faulty or connections poor. Any other ideas before I hit the dealership.

Thx dave

whopper

checking the bypass would probably be a good idea, along with giving the various connectors a look at. Did you hit any bumps in the road, or drive in rain that might have jarred something loose or gotten soaked?

If the MAP sensor had a problem shouldn't it throw a code of some sort? Can always check it's connection though.

cannuck

after some academic searching i found the lower maf to be held in with only 1 screw much like the top the screw was loose the lower maf was loose. wondering if you can put sealant to seat it better. anyway that seems to have solved the problem i guess the computer needs to remap itself to get me back up to were it used to be but it seems to pull a little better so basically it was a boost week

donbrew

DO NOT use anything that contains silicone!!!!!!!!!! Unless you really want to start replacing O2 sensors on a regular basis.

firemangeorge

Don't use any type sealer. If you're worried about having a leak, then you should replace the O-ring with a new one. A light coat of clean engine oil on the O-ring is what's recommended by GM when installing the Tmap sensor.

Here's a picture of both the upper and lower stock Tmap sensors. The O-rings(in blue) should be available thru your dealer. They will be the same size for the Bosch sensors used with the GMTU.

cannuck

The bosch 3 bar only have one screw hole to secure them

firemangeorge

One does. The other has both screws.