2004 Infiniti M45FACTORY OEM SERVICE PROCEDURE

9. Check Injector

  1. Turn ignition switch OFF.
  2. Confirm that the engine is cooled down and there are no fire hazards near the vehicle.
  3. Disconnect all injector harness connectors.
  4. Remove injector gallery assembly. Refer to FUEL INJECTOR AND FUEL TUBE . Keep fuel hose and all injectors connected to injector gallery.
  5. For DTC P0171, reconnect injector harness connectors on bank 1. For DTC P0174, reconnect injector harness connectors on bank 2.
  6. Disconnect all ignition coil harness connectors.
  7. Prepare pans or saucers under each injector.
  8. Crank engine for about 3 seconds.

    For DTC P0171, make sure that fuel sprays out from injectors on bank 1.

    For DTC P0174, make sure that fuel sprays out from injectors on bank 2.

    Fuel should be sprayed evenly for each injector. 

    Fig 1: Checking Fuel Sprays Out From Injectors
    G00795911Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG 

  1. OK: GO TO 10.
  2. NG: Replace injectors from which fuel does not spray out. Always replace O-ring with new ones.
Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.

Shop Manual-Ready ToolsCompare Repair QuoteQuote Shield Pro

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.

Rather have a pro handle this?

A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.

Comes to youSame-day available12-month warranty
Get a Free Quote

No obligation. See pricing before you book.