Powertrain, generic (extended)

P2E6A System Too Lean During Cylinder Deactivation Bank 2

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P2E6A applies the lean test to bank 2, the cylinder row without cylinder 1. GM sets it on the 4.2-litre twin-turbo V8 of the 2019 table 19OBDG07 when the trim factor learned for deactivation mode on bank 2 exceeds 1.23 while stable; Type B. The engine closes the valves of four cylinders and fires in the order 1-4-6-7, so on GM's odd/even bank split only cylinders 4 and 6 keep working on bank 2, and a single weak injector there weighs heavily. A separate camshaft-driven high-pressure pump feeds each bank, so a pump problem can also stay on one side. CARB requires the fuel system to be watched for any fault that pushes emissions over the limits. A lean trim on both banks during deactivation points to a shared cause such as an intake leak.

Likely causes

Weak injector on cylinder 4 or 6, which carry bank 2 in deactivation mode
Bank 2 high-pressure fuel pump delivering too little
Deactivating rocker on bank 2 letting air pass into the exhaust
Exhaust leak ahead of the bank 2 oxygen sensor

Symptoms

  • Check engine light after two trips
  • Hesitation at light load in deactivation mode
  • Often no noticeable change in normal driving

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–2,000
Time1–8 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

fuel injectorsdeactivation solenoidsintake system

Related codes

P2E68P2E6BP2179P0174

References: gsi.ext.gm.com, law.cornell.edu, gm-efi.com, en.wikipedia.org.