Lean mixture Bank 1 & 2.

I just replaced a fuel spider due to a #2 misfire. Truck ran like crap before, runs much better now. Thought it was all good, as no CEL came on.. for awhile. After 10 minutes or so cruising at 70, CEL comes back on. Check the code, and its P0171 and P0174. After some research, it looks like this is usually caused by a vacuum leak. Which is possible since I just had the manifold and some vacuum lines dissected. Well the idle is spot on, and carb cleaner made no effect on the idle. Also heard MAF, but there is no code for that, no other side effects, and I just cleaned it the other day.



Some of you may have read my other posts and know that I am putting this truck back together after the PO let it sit half assembled for 6 years. So I do not know the history on it, like how the performance was or the MPGs were. I myself have put on less than 50 miles (75% of those were today) and it has never been running at 100%. But performance SEEMS to me like what I would expect from a 4.3 in a full size pickup, not stellar, but not really lacking. At least until 50 MPH, then it fights just to get to 70 mph. MPGs seem worse than I would expect. I put in $10 (little over 3 gallons) and it was gone in less than 30 miles. Which doesn't make sense if it's running lean?

Oh, and another question since I am here, kind of unrelated though. At 70 mph, the truck says it is running at 2.1k rpms. That doesn't sound right to me.. Like I said, it struggles to get up to 70 after about 50 or so. At 50 it reads 1.9k and I have to give it lots of gas to get up to 70 at 2.1k rpms. Just seems low to me...

 

Cleared the codes. The code for bank 1 came back, but the one for bank 2 did not. But now I have a code for evap purge flow, P0441. What might that be? And could they be related?