Hooligan32 P0420 FORD - Catalyst System Efficiency Below Threshold Bank 1Possible causes
- Three way catalyst converter Bank 1
- Exhaust tube
- Intake air leaks
- Fuel injectors may be faulty
- Fuel injector leaks
- Spark plugs may be faulty
- Improper ignition timing
- Engine Control Module (ECM)
Tech notes
The most common cause it the three way catalyst converter Bank 1. Changing just the O2 sensor usually don't repair the problem. If the P0420 code is combined with other codes, try fixing the other codes first.
When is the code detected?
- Three way catalytic converter Bank 1 does not operate properly.
- Three way catalyst converter Bank 1 does not have enough oxygen storage capacity.
Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
P0420 FORD Description
The Engine Control Module (ECM) monitors the switching frequency ratio of heated oxygen sensors 1 (front O2 sensor) and heated oxygen sensors 2 (rear O2 sensor).
A three way catalyst converter (Manifold) with high oxygen storage capacity will indicate a low switching frequency of heated oxygen sensor 2. As oxygen storage capacity decreases, the heated oxygen sensor 2 switching frequency will increase.
When the frequency ratio of heated oxygen sensors 1 and 2 approaches a specified limit value, the three way catalyst malfunction is diagnosed.
P0136 - O2 Sensor Circuit Malfunction Bank 1 Sensor 2Possible causes
- Rear Heated Oxygen Sensor Bank 1 harness is open or shorted
- Rear Heated Oxygen Sensor Bank 1 circuit poor electrical connection
- Faulty Rear Heated Oxygen Sensor Bank 1
- Inappropriate fuel pressure
- Faulty fuel injectors
- Intake air leaks may be faulty
- Exhaust gas leaks
Tech notes
Replacing the rear O2 Sensor bank 1 usually takes care of the problem.
When is the code detected?
The P0136 code is set when the Engine Control Module (ECM) detects that the rear O2 sensor signal voltage is out of range for an extended period of time.
Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
- High Fuel Consumption
- Excessive Smoke from Exhaust
P0136 Description
The heated oxygen sensor 2 (HO2S), after three way catalyst (manifold), monitors the oxygen level in the exhaust gas on each bank. For optimum catalyst operation, the air fuel mixture (air-fuel ratio) must be
дальше мне лень
по меньше всего меняли по больше было толку. трещина на катушке не говорит о том что она пробивает и таму подобное.