After a brief respit from idle problems and codes, the problems returned. Zipping under the hood with wrench in hand I found the EGR bracket bolt tight! Dang. After the vac hose check and spray with carb cleaner drill, I could not find a leak source. Another 2 hr. trip to the Isuzu shop finely got results. They felt it was the intake gasket in the front area. Hmm, the codes say lean in both banks. Both gasket leaking? So off came the S/C and manifold. New gaskets and the same problem returns. Then the search goes to the back on the S/C chamber in the back next to the firewall. Another drilled through threaded hole holds on a bracket for the fuel line. The bolt is loose and inaccessable. Off comes the S/C again and the the bolt is LockTited in place. Problem solved, at last. Two different bolt leaks and two different fuel line leaks in a few months has been a nasty exercise.

As to the 1441 code I have had since the S/C went on. The tech said a vacuum line from the back of the S/ C went to the evap control system, but it should go to the orphan plastic switch mounted on the front of the engine. Alpine just capped it off. The tech said the evap system cycles on and off and should not have continous vac. Hose added and port capped. Problem solved.
Roy