knock warning light?

[fat-controller]

sorry dont know if this is in the right section,just wanted to know mate of mine has a 99 type ra and sometimes the boost wont reach over 0.5 bar,if it was the ecu cutting back the boost due to knock would there be an engine light or would anything show up in a diagnostics test thanks for the help.

 

[Scoobymaniac]

The ecu won't restrict boost or rev's unless in a "limp" mode.
Chances are your friends problem in related to a faulty boost solenoid or a MAP (Manifold Absolute Pressure) sensor fault.

You could get a diagnostic check but this may not reveal the problem, best to get a good mechanic that knows subaru's to have a look.
Speak to some of the traders on here and they'll sort it out no bother