Check your vacuum tubing on top of the EGR (silver UFO Looking metal circle.) There should be a plastic tubing with a rubber elbox shaped boot plugged on to the top of a nipple. Make sure that isn't cracked, broken, missing, etc.
(BE CAREFUL, the tubing will be VERY BRITTLE from age)
If that is fine, you need to search for how to clean the DPFE, and then how to clean out the "EGR passages" next to the TB
That should clear your 420 and (I am venturing) your 0133.. the 133 is a lean code.. 420 is your egr not working. (normally.. your egr not working will cause you to run lean, if the tubing is cracked, etc. a two-fer!)
Ray
