here's the story. About a year ago I started throwing this low boost code I ended up cleaning the map sensor and it went away till a couple days ago. It comes on and throws me into limp mode and gives me maybe quarter throttle. I tried cleaning the sensor again and didn't do anything. The other deal I was wondering. I have notice a slight reduction in boost pressure down to about 27 from 29 and when I'm gettin on it hard around the max boost I can hit and around 2400rpm I start to hear a mild scream from the motor? If I just rev it I don't hear it's just under a good load. So could there be a slight boost leak or is it something else should I just try replacing the sensor. Just needing some advice where to start. I can't find a boost leak I think I would just buy the aftermarket boots.

 

If you have the stock boots,I would change them.It will be a good start and investment.As for the map sensor I would replace it after 365,000 miles. I think you got your moneys worth,with 27 psi and it giving a low boost code.Might want to check the turbo out for any problems,shaft play,oil residue,..etc.Might want to check the intake horn gasket to.

 

actually I checked them out this weekend all is well turbo don't seem to have too much play no oil in it either but there is a tiny bit of play. intake horn gasket is fine too just checked it I am ordering a map sensor today and will be ordering a boot kit later this week got some good quotes on it. guess we'll see from there.

 

OK quick update got the leak fixed I took off the old lift pump and didn't find some short bolts to put back in its place and at high boost it would blow through so I got some new bolts in and back up to 28psi boost and new map sensor on the way.

 

so I got good boost numbers now that is not an issue but I still throw the code every now and then and can't figure it out. It has a brand new map sensor as of last week and keeps kicking me into limp mode. Could it be the banks box? it acts as a boost fooler too so maybe it's screwin up?

 

Take it out of the loop,Right now I have a 3rd gen in the shop with a banks on it same thing poping low boast codes.