Should I buy this 5ktqa?

[Orin Eman]

> 
> Doesn't the check engine light under boost mean that the ECU has gone to
> full retard but is still getting knock? That's my recollection, though I
> can't say for sure. I bet Orin knows...

It can happen over 0.7 bar - doesn't actually need 'boost'.
You need to be over 0.7 bar for quite a while for this to happen.

When this happens, the codes should be pulled _before_
shutting the engine off.  I'm not entirely sure, but it
could be a different knock sensor error.

Now if it is the max retard error, it could be a noisy lifter,
really bad gas, or a defective hall sensor (on MAC11B/C).

Orin.