Hi there! Newbie here. I couldn't find the Quest forum so I will post this here and hope that a moderator will move it to the correct forum.
1999 Mercury Villager/Nissan Quest Knock Sensor Relocation.
1. Knock Sensor - Advance Auto Part/Number S8731
2. Carquest by BWD Pigtail P/N S28423
3. Dorman Butt Connector P/N 85480 (or quick connect terminals)
4. Wire Conduit P/N 85632
5. Dorman 18 gauge wire P/N 86753 (preferably white color)
6. Autocraft 3/8 inch ring connector P/N 86417 (optional)
7. Flange Bolt (Crown Bolt) 5/16” – 18 x 1”, Home Depot P/N 68278
8. Electrical Tape P/N 4218-BA-40
1. Socket wrench (to disconnect battery negative terminal, to install knock sensor and disconnect Connector C149)
2. Flat head screw driver (to unhook Connector C149)
3. Wire cutter (to cut and strip wires)
4. Pliers (to crimp butt connectors)
1. Disconnect battery negative terminal
2. Screw Knock Sensor (with flange bolt) into engine block next to A/C compressor. The hole is already pre-manufactured.
3. Connect pigtail into K/S. Looking towards the K/S, the left terminal is the K/S wire and the right terminal is the ground wire. Splice 18 gauge wire to the K/S wire and extend K/S wire to the Connector C149. C149 is near the power steering reservoir. C149 is the big black rectangular connector (2” x 2 “ x 4 “), which has a bolt in the middle.
4. Connect K/S wire to the back of C149 You may have to unbolt it and using the screw driver, unclip it from the metal stand to give yourself more room to cut and splice the K/S wire. Cut white wire from Pin 37 about 2 inches from the back of C149. Splice K/S wire using butt connector to the white wire towards back of C149. Looking at the back of C149, Pin 37 is the 4th from the top right and has a white wire. This white wire leads to the PCM.
5. Reinstall C149.
6. Use wire conduit to cover K/S wire. Tape up the ends of the conduit. Reinstall battery ground terminal. At this point the K/S relocation is complete.
7. Optional. If you want, you may extend the ground wire from the pigtail (right side) and attach it using a ring connector to the ground on the side of the right fender near the power steering reservoir. There is already a screw with another ground wire there. This step is not necessary as the engine block has a direct ground to the PCM.
Good luck and happy driving without the P0325 code anymore.