Safety Warning

DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.

2004 Infiniti FX45FACTORY OEM SERVICE PROCEDURE

Overall Function Check

Use this procedure to check the overall function of the three way catalyst (manifold). During this check, a 1st trip DTC might not be confirmed.

With GST

Turn ignition switch OFF and wait at least 10 seconds.
Start engine and keep the engine speed between 3,500 and 4,000 RPM for at least 1 minute under no load.
Let engine idle for 1 minute.
Open engine hood.
Set voltmeters probes between ECM terminals 16 [HO2S1 (bank 1) signal], 35 [HO2S1 (bank 2) signal] and ground, and ECM terminals 55 [HO2S2 (bank 1) signal], 74 [HO2S2 (bank 2) signal] and ground.
Keep engine speed at 2,000 RPM constant under no load.

Fig 1: Using DVOM To Test Overall Function (1 Of 2)
Courtesy of NISSAN MOTOR CO., U.S.A.

NOTE: If the voltage at terminal 16 or 35 does not switch periodically more than 5 times within 10 seconds at step 7, perform trouble diagnosis for DTC P0133, P0153 first. See DTC P0133, P0153 HO2S1 .

Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.
• Brakes feel soft, pull hard to one side, or make grinding noises.
• The engine overheats, stalls repeatedly, or misfires under load.
• You are missing required tools, torque specs, or safe lifting equipment.
• You are not confident in the next step or safety outcome.