14721-PXK-000 Honda VALVE, EX. (Honda Code 6989586).

Introduction
The problem that is identified below does not have a known permanent solution. Use the temporary solution that is listed below, until a permanent solution is identified.Problem
Failure to route or handle NOx sensors properly can result in premature failure of the sensor or wiring.Solution
Parts
Table 1 contains the part numbers.
Table 1
Qty Part Number Part Name
1 359-9171 Nitrogen Oxide Sensor As
1 372-1187 Nitrogen Oxide Sensor Gp
1 379-0138 Sensor and Mounting Kit (NITROGEN OXIDE)
1 441-5127 Nitrogen Oxide Sensor As
1 480-5469 Nitrogen Oxide Sensor Gp General Handling Procedures
Illustration 1 g06209503
(1) Sensor Probe
(2) Sensor Probe Grommet
(3) P-Clip
(4) Sensor Harness
(5) ECU Buffer
(6) Main Wiring HarnessUse the following list below as general handling guidelines for the NOx sensor and wiring harness.
Do not unplug the NOx sensor cable when the sensor is powered on, damage to the engine ECM may occur.
Avoid impacting the NOx sensor, dropping the sensor could cause permanent damage. If the sensor is impacted, discard the sensor.
Handle and store the NOx sensor in a clean, dry area that is free of contamination and inclement weather.
The sensing unit protective cap should not be removed until the sensor is ready for installation.
Do not paint any part of the sensing unit.
Allow the exhaust system to cool before removing the sensor.
Do not clean any part of the sensor with chemical cleaners.
Shipping boxes should be transported and stored in a closed condition. Store sensors in the original closed shipping box until the sensor is ready for installation.
The maximum storage time for sensors in spare part packaging is 2 years after production.
Sensors should be stored in a temperature range of −40° C (−40° F) to 105° C (221° F).
Avoid temperature shock when opening a shipping box. Avoid a temperature difference of 5° 5°C (41° 41°F) between sensors and the environment. Allow at least 4 hours for the sensors to reach ambient temperature before opening the box to avoid condensation on the parts.
Do not open the shipping box with a knife that can deeply penetrate the box. Knives can damage the sensor or sensor cables.NOx Sensor Installation Procedures
Illustration 2 g03695896
(1) Electrical Connector
(2) Cable (varnish tube sleeve)
(3) Grommet
(4) Hex Nut
(5) Threads
(6) Protective Cover
(7) Mounting Tabs
Mount the ECU with hardware.
Install the ECU sensor harness clamp.Note: Do not bend the cable sharply. Route the sensor cable and secure the cable as the original cable was installed.
Remove the protective cap from the sensing unit. Do not lubricate the threads of the new sensor. The threads come pre-lubricated from the factory.Note: Non-metallic anti-seize is the only approved thread lubricant to be used when reinstalling a sensor.
Illustration 3 g06209614
Place the sensing unit in the mounting boss on the exhaust outlet elbow and turn the hex nut by hand until tight.Note: Hold the base of the sensing unit neat the grommet so the cable does not twist while turning the hex nut. The maximum allowable cable rotation after tightening is 180 degrees.
Tighten the hex nut to 50 10 N m (37 7 lb ft).
Carefully place sensor harness inside the p-clips, ensuring not to pull on the harness or to put tension on it.
Connect the sensor wiring harness to the sensor buffer module and install the cable strap.
Illustration 4 g06209618When NOx sensor installation is complete, inspect the exhaust insulation at the exhaust outlet and the flex coupling insulation. There must be adequate air flow around the NOx sensor probe to prevent overheating. Refer to Illustration 4.
Illustration 5 g06209623
(8) Sensor Probe GrommetSensor probe grommet (8) has a maximum temperature of 200° C (392° F).