just wanted you to know the major demon has been cleared....it went like this.......catalytic convertor was plugged....caused extra hot backflow thru egr, which burned a hole in the upper plenum causing a vacuum leak.....I got suspicious when after changing the cat con, I still had really bad surge....changed throttle body gasket...no improvement....could just barely get it running had a buddy listening under the hood, and found I had another intake leak....the burned plenum.....patched it (the 2 holes were fairly small) with JB weld it's working very well now...back to pre plugged convertor in terms of pwer and running quality......still getting engine code PO405 and 404....more to work on
p.s. egr valve is new also...about400 miles on it
