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Toyota Corolla Repair Manual: Catalyst system efficiency below threshold

Toyota Corolla Repair Manual / Diagnostics / Sfi system / Catalyst system efficiency below threshold

Dtc p0420 catalyst system efficiency below threshold (bank 1)

Inspection procedure
Hint: read freeze frame data using the hand-held tester or the obd ii scan tool. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, it is usefu ...

Circuit description
The ecm compares the two waveforms of the heated oxygen sensors located before and after the catalyst to determine whether or not the catalyst performance has deteriorated. Airfuel ratio feedba ...

Other materials:

Precaution
1. Do not handle refrigerant in an enclosed area or near an open flame 2. Always wear eye protection 3. Be careful not to get liquid refrigerant in your eyes or on your skin If liquid refrigerant gets in your eyes or on your skin.  wash the area with lots of cool water. Cautio ...

Inspection procedure
1 Check side squib(lh) circuit(airbag sensor assy center front seat airbag assy lh) Disconnect the negative () terminal cable from the battery, and wait at least for 90 seconds.  disconnect the connectors between the airbag sensor assy center and the front seat airbag assy (lh ...

Valve clearance
Adjustment 1. Remove cylinder head cover no.2 Remove the 2 nuts, 2 clips and cylinder head cover. 2. Disconnect engine wire Remove the 5 clamps from the 5 clamp brackets. Disconnect the 4 ignition coil connectors. Remove the bolt and nut installing the engine wire ...

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