1. Inspect for wire harness chafes on the Fuel Injection Control Module (FICM) wiring harness retaining bracket and at the alternator.
2. Clear trouble codes then wiggle test the related injector connectors to see if the trouble codes can be repeated.
3. If the harness checks OK, replace the affected injector connector pigtail per bulletin.
4. See TSB's #09-06-04-034, #05-06-04-047C, #06-06-04-026A, #3238E for more detail regarding fuel injector harness chafing and injector pigtail repairs.
5. You can stop at a Chevy dealer parts dept and ask them to print out the TSB's or you can try to Google each TSB # and you may find them on the internet, usually in a PDF file.
#2 Fuel Injector Wiring
Fuel Injector Connector
See TSB: #09-06-04-034, #05-06-04-047C, #06-06-04-026A. NOTE: Cylinders #1, 3, 5, 7 are on the Right Hand (RH) side of the block and #2, 4, 6, 8 are on the Left Hand (LH) side of block.