How To: Nissan Altima Repairs - Head Light / Oxygen Sensor P0420

 -- 2005 Nissan Altima 2.5S      --- 

-- Headlight Repairs/Bulb Replacement -- 

There are 4 fuses 15A for each of the head lights. These fuses are located near the windshield wiper fluid reservoir tank.  The black box, is label with the fuse diagram.

H/L R/H Low

H/L L/H Low

H/L R/H Hi

H/L L/H Hi

--- L/H - driver side headlight -----

replacing the light bulb can be accomplished without remove the entire head lamp assembly.  It's misleading, thinking the headlamp is held up by the 2x 10mm bolts, holding the lamp assembly to the frame.

The short easier way:

1. remove the air filter assembly (unlatch the air filter box, remove air filter, and move/away the air intake)

2. remove the 1 single bolt, connecting the air filter box to the frame.

3. remove the air intake duct sitting on top of radiator (remove 4 plastic tabs), and disconnect it from the air filter intake box

4. pull the air filter intake box, straight up.

Follow the headlight wires, and disconnect the housing, seals etc.  One-for-One swap for new parts.

Fully connect the wires, be sure that the light bulb is properly grounded first. Do not test the lights until, the light bulb is in the light assembly, and grounded.

 -- OXYGEN SENSORS      --- 

The repair manual/suggests the following for resolving ODBC II code P0420:

Service Engine Code  P0420
- check for leaks (affecting sensors), wiring etc
- replacing rear/down stream oxygen sensor first
- replacing up stream oxygen
- replacing the catalyst converter

REPAIRS:

PART 1:  BUY PARTS
      --- AutoZone, O'Reilly  offers BOSH OEM fit up stream sensors for $100
      --- SAME PLACES - BOSH OEM FIT sensor for down stream sensor $90
     ---  get a tube of "high heat" anti-seize compound
     --- A bottle of PB blaster spray to loosen metal/sensors

PART 2:  TOOLS
     -- 10mm and 12mm socket wrench
     --  hex key (to remove engine conver)
       -- adjustable wrench (to remove oxygen sensor)
     - flat screw driver (to un-click wire harness connector)
      -- Floor jack and JACK STANDs (to remove down stream sensor)


PART 3A: - REPAIRS, UP STREAM SENSOR

-- replacing front/up stream oxygen sensor second ( first - was jn error)

* remove the engine plastic cover (4 hex screws), easier access to remove the o2 sensor connector
* remove front heat shield 4 screws 10mm
* carefully unhook o2 sensor wire from the heat shield clip
* electrical connector - rotate/un-clamp (gray)
* use a flat screw driver to un-clip the connector and pull back
* locate the black bracket (holds the sensor and the engine plastic cover mounting point)
* the 02 wire is too short, either (cut it first), or rotate the bracket, so the bracket can be slide off.
* bracket is hold by 2 bolts - 12mm, remove the top one, and loosen the bottom one
* rotate the bracket and un-clip the 02 sensor connector
* remove the o2 sensor on catalyst converter 

PART 3B: - REPAIRS, DOWN STREAM SENSOR

* JACK UP the vehicle safely (passenger side)


 -- Engine Oil Change ----
Oil Type - 5W-30
Capacity - 4 1/2 qts, with filter change
Capacity  - 4 1/4 qts - without filter change
Oil filter - Frame TG7317 (Tough guard 6x of average dirty holding-retaintion)
              or Frame HM7317 (high mileage)

 -- Windshield Wiper Blades ----
02-05 Altima         26 driver / 17 passenger