Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

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Backfires and Afterfires

SYMPTOM:
Fuel ignites in the intake manifold or in exhaust system making a loud popping noise.

POSSIBLE CAUSE ACTION


EGR open all the time Check EGR system in "Testing Procedures" in Emissions

Leaking EGR gasket

Air management valves Check Air Injection system in "Testing Procedures" in Emissions

Deceleration valve Check valves for proper function.