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How to Replace O2 Oxygen Sensor 02-03 Nissan Altima

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  1. step : Removing the Oxygen (O2) Sensor (0:45)
    • Disconnect the oxygen sensor wiring harness with a flat blade screwdriver
    • Remove the O2 sensor with an O2 sensor socket and a ratchet
    • If the socket expands cut the O2 sensor wires with wire cutters
    • Remove the O2 sensor with a 7/8 socket and ratchet
  2. step : Installing the New Oxygen (O2) Sensor (3:04)
    • Twist the new O2 sensor into place
    • Tighten the O2 sensor with an O2 sensor socket and a ratchet
    • Connect the O2 sensor wiring harness

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Hi, I'm Don from 1A Auto. I hope this how-to video helps you out, and the next time you need a part for your vehicle, think of Thanks.

In this video, we're going to show you how to replace an upstream O2 sensor on this 2003 Nissan Altima with the 2.5L, 4-cylinder engine. The items you'll need from this are a new upstream O2 sensor from, a flat blade screwdriver, a 7/8 inch O2 socket from, and a ratchet. In our worst case scenario, we'll also need a pair of wire cutters and a pair of regular 7/8 socket. Because of the location of this O2 sensor, you can't actually use a 7/8 inch wrench, but you do need this special socket with the cut out that accommodates the wires on the O2 sensor. It's the only way to reinstall a new O2 sensor on this particular vehicle. We do sell it; we offer it in kits with the O2 sensor. To remove it, we do end up actually using this 7/8 socket and just cutting the wires, and we'll explain more of that later.

The upstream O2 sensor we're working on is located right here. Disconnect the O2 sensor harness. It's the green connection. You have to press a tab and pull it apart. Now you'll see that the harness is actually clipped on. You just want to unclip that and pull it down. Now here's that special socket, and you just slip it right over the O2 sensor. Now attach your ratchet. That socket is good because you don't have to worry about the wires because they come right out of that slot. The only problem with it is the big slot in it lets the socket expand so if the O2 sensor is in there really tight (like this one is) the socket kind of expands and kind of slips on to the O2 sensor.

What we'll need to do is basically just cut that wire with a set of wire cutters. Then we're going to use a solid 7/8 inch socket and slide it right over there. It has to be a deep socket. Put the ratchet on there and remove the O2 sensor. Just pull the O2 sensor up and out.

You can see the one on the top is the old one and it's in very rough shape. It's actually misshapen. The lower one is the new one from 1A Auto and it's an exact match.

You want to feed your new O2 sensor down into place, and just twist it in by hand to start. Now, you want to use that special O2 socket with cut out for the wires, and just tighten the O2 sensor into place. We'll fast-forward as Don does this. Now reconnect your harness and just clip that connector back up onto that bracket. Now you're all set.

We hope this video helps you out. Brought to you by, your source for quality replacement parts and the best service on the Internet. Please feel free to call us toll-free, 888-844-3393. We're the company that's here for you on the Internet and in person.

Tools needed for replacement:

    Pliers, Cutters & misc Wrenches

  • Wire Cutters

  • Ratchets & Related

  • Ratchet

  • Screwdrivers & Related

  • Flat Blade Screwdriver

  • Sockets - SAE

  • 7/8 Inch Socket

  • Specialty Tools

  • O2 Sensor Socket

2003 - 2005  Infiniti  FX45
2003 - 2004  Infiniti  M45
2002 - 2005  Infiniti  Q45
2002 - 2003  Nissan  Altima
2002 - 2003  Nissan  Sentra
2002 - 2002  Nissan  Sentra
2004 - 2004  Nissan  Sentra
2003 - 2003  Nissan  Murano
2006 - 2006  Infiniti  Q45

02-06 Infiniti, Nissan Multifit Upstream 4 Wire O2 Oxygen Sensor (15.2 Inch Lead)

Nissan Infiniti O2 Oxygen Sensor DIY Solutions EMS00207

This part replaces:

  • Standard Motor Products NA
  • OE # 226902A000
  • Walker Products Inc. 250-24452

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