I am completely at a loss here. I've posted this already, but not gotten anywhere, just throwing it back out there.
Whenever my car gets warm, after about 5 min (won't do it when it's cold) I get a check engine light whenever I hit the gas!!!
It's a code for the pressure sensor, and it shows up whenever it hits 0 vacuum.
It has nothing to do with the turbo, because it will do it down at 1500 rpms, (and everywhere else) the instant I hit the gas and get 0 manifold vacuum. (essentially instantly)

I have tested the pressure sensor a few times, (again last night) and it reads perfectly.

It's been doing this since BEFORE the turbo was on.

It goes away when it's super hot out (80 degrees+)

The car also will NOT ever go into closed loop! I just replaced the o2 sensor too, and I can't get it to go into closed loop at all. This is just s recent problem.

I have a SMALL vacuum leak at the manifold, but I doubt that would cause that much issue. Plus, this is a longstanding problem, and the leak is very recent.

I did a regrounding about a year ago, I took one wire, hooked the brown/black wire at all my sensors together(at the sensors) and then ran it to the firewall. Maybe I'm getting some sort of ground loop or something.. I'll try taking it off.
Any ideas at all would be greatly appreciated. As soon as everything on the car is fixed and its 100%, it's for sale!
Dan

 

Hm.. the only sensors I grounded were the TPS, AFM and pressure sensor... not the water thermosensor. Maybe I'll try that too, since it only does it when the engine is warm.
There is no noticable difference in the engine running when the light comes on, but it worries me because it goes to the pressure sensor failsafe value of 30inHG, which is a lot of vacuum... TOOOO much advance to have under boost.

 

have you chacked that the wire to the ecu is good? what code number is it?

 

Code 13. Pressure sensor.
One test I havn't done is a voltage test off the ECU while driving.

 

yah it might a bad wire. it reads code 13: open or short in pressure sensor circuit etc etc

 

888888
The car also will NOT ever go into closed loop! I just replaced the o2 sensor
too, and I can't get it to go into closed loop at all. This is just s recent problem.8888888

How did you determine that it is not going into *closed loop*?

 

Which model ECU?
Which model pressure sensor?
Some combinations don't work together..

My N370 sensor failed, so I installed a FCD.
Now the ECU is happy - It sees the FCD & thinks all is well.
My only snag is no high boost timming retard.
The replacement sensor is comming soon.

 

I know it's not going into closed loop because I don't see the familiar cycling of the AFR at cruise- it's stuck at about 13:1.
I would have thought that if the circuit was bad, the light would eb on all the time, not just at 0 vacuum (actually a tiny touch below it) and above.