c13- IAP sensor
c21- IAT sensor
c23- TO sensor
c28- Secondary throttle body actuator
c29- STP sensor
With that many codes id be looking at your ecu connections and for any corrosion etc in the main relay and fuse box etc
If you have taken the airbox off at some point recently pretty much all those can go off if everything wasnt put back and connected properly also.
Bookmarks