My engine check light comes on intermittently, but recently for longer and longer.
When it is on the engine cuts out at about 3800 rpm depending on boost. If I use light throttle openings it can rev ok and not cut out. It seems like the ECU is not allowing the engine to use high boost and cuts the fueling. Its a tad frustrating!
I've connected the wires under the dash and the error code indicates the problem to be the pressure exchange solenoid valve (code 45). I have swapped it for a new one, but the problem remains. I've tried resetting the ECU, disconecting the battery, new rubber tubing from the inlet manifold to the valve, all to no avail.

Any one got any ideas?

 

Actually 45 is both Pressure Sensor and Pressure Excange Solenoid Valve
(isn't it?)

Its more likely to be problems with the former.
The latter just opens at first ignition on (before starting) to let the main pressure sensor recheck what '0' / ambiant pressure is
(or thats my understanding anyway) and so don't see how it could go wrong (unless it was leaking ...?)

Might be worth connecting a boost/vac gauge to the various points in the system to check they are seeing approx the same thing

Engine cut out (deliberately by the ecu) should only happen in two main scenerios
1. check engine light on will limit you to 4500rpm exactly
You are getting cut out before here, so probably not this
2. If it thinks overboost (approx 18psi ??) is occuring
This sounds like what it thinks is happening

One crude but simple test would be to put a simple bleed off before the pressure sensor (or even disconnect entirely), so that it only sees low pressure (even if it is faulty and overreading, and drive very gently, then with increasing vigor, to see if it responds better
DO NOT drive hard, as your real overboost protection is short circuited. Plus the fuelling (and ignition) is probably running wrong and don't want to run too lean or start knocking

Good luck

 

I've checked all my hoses and wiring which all look fine. Still the check engine light comes on.

However, if I swap the two vacuum pipes around on the solenoid, the light goes off and the car drives normally until the light reappears.

What sensor am I fooling? I think it must be the pressure sensor, but am I missing something?