I just dropped a '93 L67 from a PA Ultra into a '93 LeSabre that is running great with no problems except that under moderate throttle (~40-50%), the MIL comes on and is setting DTC 57 for the Boost Control Solenoid (the Service Manual isn't being of much help). When this happens, the engine seems to bog down or stumble somewhat, but upon releasing the throttle, everything goes back to normal and the light goes out. :icon_conf Under normal acceleration this doesn't happen nor does it under fairly heavy throttle (~75-80%), and the engine pulls great! All vacuum lines are new and intact and the supercharger/lower intake gaskets are new along with the O2. I run only 92-93 octane and the PCM is the one from the PA Ult. I'm pretty new to the L67 engine so any input or experience here is greatly appreciated!! Thanks!