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

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

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Engine And Exhaust

CATALYTIC CONVERTERS
On vehicles equipped with catalytic converters, the following conditions must be observed:

^ Use only "UNLEADED FUEL."
^ Avoid running out of fuel.
^ In case of poor engine operation (misfiring), avoid driving the vehicle and correct the problem as soon as possible.
^ Do not disconnect any spark plug wires with the engine running.
^ Avoid push starting the vehicle.
^ If running on a dynamometer, make sure the catalytic converter is well ventilated.
^ Use caution when working near the catalytic converter to prevent the possibility of burns.

OXYGEN SENSORS AND SILICONE
CAUTION: Do not use silicone based products on an oxygen sensor equipped vehicle to avoid damaging the sensor.

COMPRESSION TESTING
TIP: When performing a compression test, remove the fuel pump relay fuse, and disconnect power to the ignition (This will stop fuel flow to the injectors and prevent engine from starting).