...just an update...had a reliable and knowledgeable auto tech i trust say, based on my description of the this random behavior, he suspects a "lazy" 02 bank 2 sensor, especially when I told him I had random P0174 lean bank code appear and disappear w/o any pattern...soooo...since 02's are relatively cheap, gonna throw one in, provided I can GET the sucker off-have never done one & not a lot of "swing" room where it is located....not doing this right away, but I will be sure to come back and comment...I have a friend who I will be installing one on his '99 Dakota-will be good practice (gotta love friends who'll allow you to use their vehicle to "guinea pig" learn on....lol)...soooo... consider this thread resolved, sorta

 

just an update...still havent replaced either o2 B2S1 or o2 B2S2, as it is next to impossible to get any "swing and Leverage" room on it w/o removing the pass side torsion bar..still have the random Hi Rev issues...grrr

 

another update...well, tried to replace 02 sensors...as I couldnt get "swinging room" for a wrench, I disconnected the front 4WD driveshaft and lower'd the Y pipe (to my astonishment, the header stud nuts didnt give me a hard fight) then proceeded to work on removing the B1S1 02.....used hi heat 1st, more than 1 heat cycle and that darn 02 was SOO fused on, I actually RIPPED the weld bung right off the Y pipe!...now, I HAVE to get an exhaust AND 02s....grrrrr...I pity folks that have to change out 02s in the salt infested North

 

another update...new Y pipe assy and new B1 and B2 02 sensors on the Y pipes, but not the post cat 02 ....problem STILL occurs, again randomly, and now where I before had an occasional P0174 lean bank code, it now sets w/regularity.. I verified I have absolutely ZERO exhaust leaks in my repair..I'd think if i had a vacuum leak, a P0171 would appear as well, but it doesnt set...what am I chasing/missing?