Help understand these symptoms please!

[bpmcgee]

Hi,

My buddy has a 2000 1500 with the 5.3 gas engine in it. He's been experiencing rough idle/stalling when it's cold. He's also a couple of times gotten code P0171 (System too lean - bank 1).

I hooked it up to my AutoEnginuity yesterday after the truck was all warmed up. The short term fuel trim for bank 1 was between -1 and 1, while the short term fuel trim for bank 2 was about 145. Also, the Average Injector PWMs were way out balance on bank one vs. two.

So the scan tool seems to be saying that bank TWO has injector problems, and it's continually trying to richen that side. The DTC, though, said that bank ONE was too lean.

I logged the O2 sensor voltages, but I didn't have time to delve deeply into what was happening with them.

Any ideas?

Thanks,

B