Recurring codes P0325, P1114, P1126 and P420

PAYNOTHING

MEMBER
2000 NISSAN ALTIMA
2.4L
4 CYL
2WD
AUTOMATIC
258,000 MILES

Keep having return codes P0325, P 1114, P1126, P420. Not terrible gas mileage, but not good. Exhaust smells like propane when I first start it up. Smoke test shows no results. New gas cap I have replaced thermostat, coolant sensor and pig tail, nock sensor, purge valve on top. Replaced intake manifold gasket at 254,000. Motor runs great. Idle in park at cold 11000-13000. After warmed up 1000. In drive, 785-1000.

1 Reply

ASEMASTER6371

MECHANIC
52,797 POSTS

Good morning,

The 420 is most likely a cat converter issue. You can confirm by comparing the upstream and downstream voltage readings. If they are the same, the catalytic converter is bad.

https://www.2carpros.com/articles/catalytic-converter-replacement

The 114 is the coolant temperature sensor malfunction.

https://www.2carpros.com/articles/coolant-temperature-sensor-cts-replacement

The 335 is for the crank sensor failure.

https://www.2carpros.com/articles/crankshaft-angle-sensor-replacement

I attached the information below for you.

1126

DIAGNOSTIC LOGIC
Even though the engine has been driven sufficiently to raise the engine coolant temperature, the engine coolant temperature is not raised to the specified temperature due to the thermostat having a leaking seal or being stuck open.

DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE

NOTE: If "DTC CONFIRMATION PROCEDURE" has been previously conducted, always turn ignition switch "OFF" and wait at least 5 seconds before conducting the next test.

TESTING CONDITION:
- For best results, perform at ambient temperature of -10°C (14°F) or higher.
- For best results, perform at engine coolant temperature of -10°C to 60°C (14 to 140°F).

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With Consult
1. Replace the thermostat with a new one. Refer to "Thermostat", "ENGINE COOLING SYSTEM". Use only a genuine NISSAN thermostat as a replacement. If an incorrect thermostat is used, the MIL may come on.
2. Turn ignition switch "ON".
3. Select "COOLANT TEMP/S" in data monitor mode with CONSULT-II.
4. Check that the "COOLANT TEMP/S" is above 60°C (140°F).
If it is below 60°C (140°F), go to the following step. If it is above 60°C (140°F), stop engine and cool down the engine to less than 60°C (140°F), then retry from step 2.
5. Drive vehicle for 10 consecutive minutes in the following conditions.
VHCL SPEED SE: 80 kph to 120 kph (75 MPH)
If 1st trip DTC is detected, CHECK COMPONENT INSPECTION of ENGINE COOLANT TEMPERATURE SENSOR.

OR

With Generic Scan Tools
1. Follow the above procedure "With CONSULT-II".

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