★ ENGINE TECH · GM (CHEVY + GMC + CADILLAC)

GM Active Fuel Management (AFM) Smog Issues

QUICK ANSWER

AFM is GM's cylinder-deactivation technology on V8 trucks/SUVs (Silverado, Tahoe, Suburban, Escalade). Known issue: lifter failure causing misfire codes (P0300-P0308) — can prevent smog passage. Common on 2007-2014 5.3L V8s. Fix: lifter replacement OR AFM delete kit (must use CARB-approved version for CA).

Common AFM (Active Fuel Management) smog issues

Lifter failure on deactivating cylinders, oil consumption from ring wear

How to fix

Lifter replacement (~$1,500-3,500), or CARB-approved AFM delete (rare)

Typical repair cost

$1,500-$3,500 for lifter repair

Common questions

What is AFM (Active Fuel Management)?

AFM is GM's cylinder-deactivation technology on V8 trucks/SUVs (Silverado, Tahoe, Suburban, Escalade). Known issue: lifter failure causing misfire codes (P0300-P0308) — can prevent smog passage. Common on 2007-2014 5.3L V8s. Fix: lifter replacement OR AFM delete kit (must use CARB-approved version for CA).

What causes a AFM (Active Fuel Management) smog failure?

Lifter failure on deactivating cylinders, oil consumption from ring wear

How is AFM (Active Fuel Management) fixed?

Lifter replacement (~$1,500-3,500), or CARB-approved AFM delete (rare)

What does fixing cost?

$1,500-$3,500 for lifter repair