Those codes strongly suggest you have a boost pressure solenoid issue. There is a way to bypass that solenoid to see if it's your problem, when bypassed your boost should go back to normal but the CEL won't go away until the solenoid is replaced although it doesn't cost much. There is or was a picture on the forum on what hoses to move but I cannot find it just now. GDE's writeup on this says "By-passing of the on/off solenoid is very straight forward. Trace the vacuum line output from the black plastic reservoir to the input of the on/off solenoid. Remove this vacuum line and plug it directly into the turbo EVM on the port labeled "VAC". The turbo EVM is the one with the blue rubber isolator and vacuum line running directly to turbo." The "black plastic reservoir" refers to the vacuum reservoir located just behind the air box.
Note though that the P0299 code may also be due to a collapsed/melted vacuum line between the vacuum reservoir and the firewall behind/under the plastic water tank. There is at least one report of that line contacting a hot metal part and collapsing/melting (
viewtopic.php?f=5&t=61240)