P0171 & P0174 codes

[53burb]

Everybody,
I am trying to get my truck ready for emissions here in Phoenix. I am receiving these codes on the computer: P0171 & P0172. They are Bank 1 (Driver's side) & Bank 2 (Passenger side) lean. These O2 sensors are before the catalytic converters. The vehicle is a '99 NBS Silverado 1/2ton, 4x4, 4.3 V6, & 5 sp manual transmission with 143k miles.
These are the items I have done:
1. Clean MAF & verified air filter was clean
2. Sprayed carb/throttle body cleaner around base of upper intake - no change in idle
3. Cleaned throttle body with throttle body spray
4. Replaced PVC hoses (1 elbow & short length of hose)
5. Used vacuum hose to brake booster to suck 1/3 pint of Sea Foam into engine
6. Poured remaining Sea Foam into gas tank
7. Poured another brand of injector cleaner into gas tank
8. Replaced fuel filter
A few months back I changed the fuel regulator because the truck would take a few seconds before it finally fired up on the first time of the day. This didn't help at all. I ordered an AC fuel pump today & will be replacing it when it comes in. Hopefully this will help with the hard starting problem & also the codes. This will be the 3rd pump I have had in it. The original & the pump I am now going to replace. The 2nd pump is an AC pump, also. After every change I have made, I have cleared the codes using the scanner from either AutoZone or O'Reilly's. Normally, the codes come back in anywhere from 5-10 miles. After the filter change today, it took 25 miles before they came back in. Unfortunately, I have to drive the truck 40-50 milles before the ECM is reading all the inputs & is ready for the emission test. I have NOT replaced the O2 sensors because I have read that if they both get the "lean" codes at the same time, then most likely, they are reading correctly. Also, the CCs were replaced a couple of years ago, also.
Any help is appreciated because I am very very frustrated with this, other than this, the truck runs great.

Chris