P0021

Bank 2 intake camshaft mechanically OVER-ADVANCED. V6/V8 engines only. Same diagnostic family as P0011 but on bank 2. Cheapest-first ladder: (1) Live-data commanded vs actual bank 2 intake cam angle — should track within 2-3 degrees; over-advance means the phaser won't release oil pressure on command. (2) Verify oil weight matches OEM spec — wrong viscosity is the top P0021 cause. (3) Clean bank 2 OCV inlet screen. (4) Hot oil pressure test (minimum 10 psi idle, 40 psi at 2500 rpm). (5) Swap bank 2 OCV with bank 1 OCV — if P0021 moves to bank 1 (becomes P0011), OCV is the culprit. Don't replace the bank 2 cam phaser before doing oil change with correct viscosity, cleaning OCV, and pressure-testing — bank 2 phaser jobs on V-engines are 6-8 hours of labor because the cabin-side cam is buried under the intake plenum and often the cowl.

Vehicle-specific patterns: 2004-2010 Ford F-150/Expedition 5.4L 3V Triton — bank 2 (passenger side) cam phaser failure, almost always paired with P0011 or P0014, full 4-phaser kit replacement is the only fix at $1,800-$2,600. 2007-2016 Toyota Camry/Highlander/Sienna 2GR-FE — bank 2 OCV screen clog, TSB EG053-08 cleaning procedure. 2008-2014 Honda Pilot/Ridgeline/Odyssey J35 — rear-bank VTC actuator wear, paired with P0011 typically. 2007-2013 Nissan VQ35 — bank 2 secondary chain guide failure can present as P0021 instead of P0018, inspect chain before condemning phaser. 2008-2013 GM 3.6L LLT — VVT solenoid failure with TSB PIC5446. Estimated repair: $60 to $2,800.