★ ENGINE TECH · MOST MODERN ENGINES

Variable Valve Timing (VVT) Engine Smog

QUICK ANSWER

VVT is variable valve timing — adjusts valve operation for efficiency + power. Found on most 2000+ engines (Honda i-VTEC, Toyota VVT-i, BMW VANOS, GM AFM, etc.). Common smog issue: failed VVT solenoid or stretched timing chain causes misfire + emissions codes.

Common VVT (Variable Valve Timing) smog issues

Failed VVT solenoid, stretched timing chain, low oil pressure

How to fix

Replace VVT solenoid, replace timing chain + tensioner

Typical repair cost

$200-$1,200 depending on engine

Common questions

What is VVT (Variable Valve Timing)?

VVT is variable valve timing — adjusts valve operation for efficiency + power. Found on most 2000+ engines (Honda i-VTEC, Toyota VVT-i, BMW VANOS, GM AFM, etc.). Common smog issue: failed VVT solenoid or stretched timing chain causes misfire + emissions codes.

What causes a VVT (Variable Valve Timing) smog failure?

Failed VVT solenoid, stretched timing chain, low oil pressure

How is VVT (Variable Valve Timing) fixed?

Replace VVT solenoid, replace timing chain + tensioner

What does fixing cost?

$200-$1,200 depending on engine