Feel free to correct me if I've missed a step here.
Note: If any bolt feels as though it requires too much strength to loosen, use penetrating solution for the bolts. It is suggested to use penetrating solution before removing the bolts. Bolt removal should be smooth and gliding. Failure to properly take out bolts may result in broken bolts that would later need to be extracted.
Pre-planning:
1. Buy a new oil pressure sending unit
2. Get a 1-1/16 or proper socket for said oil pressure sending unit
3. Get sealant for the oil pressure sending unit
4. Have a socket wrench for the socket for the oil pressure sending unit
5. Get a Phillip's head screwdriver (for airbox)
6. Get 10 mm socket (for airbox and battery tray)
7. Get lubricant to lubricate bolts on airbox and battery tray
8. Get 13 mm socket (or proper size socket) for the top of the battery tray
9. Have the proper sockets to loosen the clamps on the battery
10. Have the proper wrench for the 10 mm, 13 mm, and other sockets.
11. Have a socket wrench extension, possible 6 inches to a foot, that will reach onto bolts with the proper socket head attached
Note: A person may want a tarp or oil pan under the vehicle in order to catch any oil drips that may come out from removing the oil pressure sending unit.
Go to the vehicle:
1. Have the vehicle off and in park
2. Pull up the emergency brake
3. Lift the hood and stand up the hood
Remove the battery [1]:
1. Loosen the bolt on the negative battery cable
2. Move aside the negative battery cable
3. Loosen the bolt on the positive battery cable
4. Move aside the positive battery cable
5. Don't let the metal of the cable wires touch each other
6. Loosen the bolt behind the battery on the rear side (13 mm?)
6.a. Use penetrating solution to help loosen the bolt
7. Remove the battery and place in safe place
8. Remove bolt from the rear side with plate and put in a safe place
Airbox top removal and bottom adjustment (for slack):
1. Unscrew the top of the air box
2. Unscrew the air hose hooked up to the airbox
3. Unbolt the airbox from the front of the vehicle mounting down the airbox (keep all bolts organized)
3.a. Use penetrating solution to help loosen the bolt
4. Remove the air intake mantle from the airbox on the left side of the air box
5. Remove the bolt on the inside, left side of the vehicle's engine bay mounting down the bottom of the airbox
5.a. Use penetrating solution to help loosen the bolt
Removal of the battery tray [1]:
1. Use 10 mm socket with socket wrench extension
1.a. Use penetrating solution when needed
2. Remove the 4 bolts on top of the battery tray. (keep all bolts organized)
3. There may be a bolt toward the front of the battery tray, that is on the vertical side of the battery tray that faces opposite to the airbox. Carefully bring the bottom of the airbox forward to the front of the vehicle to observe the 5th battery tray bolt (remove 5th bolt); the bolt is horizontal, but it's on a vertical side of the battery tray.
4. Carefully remove battery tray
Removal of oil pressure sending unit:
-> Preliminary
[2]Stand at the front, left corner of the vehicle. Lean over. Take right hand and keep close to the metal angle of the engine. As in the picture, there are two areas of metal that intersect and make a somewhat right angle. At the intersection of the right angle, move fingers forward (toward the left side of the vehicle) while touching the metal block of the engine. Slowly feel upward with fingertips while moving across the intersection. Eventually, the oil pressure sending unit will be felt with fingers. Use a light during the process, as this may may the electrical cap plug on the oil pressure sending unit more easily observed. Once the location of memorized, finding it again is not too difficult.
YouTube video [3]:
https://www.youtube.com/watch?v=sgGgs9FEnto
1. Observe oil pressure sending unit electrical cap plug
2. Pull plug from oil pressure sending unit (release red tab if it exists)
3. Place oil pressure sending unit socket on socket wrench
4. Slink socket on socket wrench onto oil pressure sending unit from the left side while inside the engine bay
5. Reach over the valve cover with left arm and firmly push socket onto oil sending unit with left hand
Note: it may work better to slink the socket onto the oil pressure sending unit from above and over the valve cover. If so, use that method.
6. Patiently wrench off oil pressure sending unit while firmly keeping socket on oil pressure sending unit; it is important to make sure that the socket is on the oil pressure sending unit all of the way.
7. Unscrew oil pressure sending unit with right or left hand when loose enough
There may be a wire or tube in the way, as such, finding the right spot to get enough turning ability with the wrench is important. Furthermore, making sure the oil pressure sending unit socket is on the oil pressure sending unit is important to ensure that the oil pressure sending unit is gripped so that it may be turned.
Prepare new oil pressure sending unit:
1. Prepare new oil pressure sending unit with sealant
Place in new oil pressure sending unit:
1. With the way the oil pressure sending unit was found by touch with fingers and the metal intersection, slowly slink the oil pressure sending unit into it's threaded slot and hand tighten into place.
1.1. Do not crossthread [4]
2. Wrench tighten in a similar manner as was done with taking it off
3. If there are specs, use them
4. Place oil pressure sending unit cap plug back on
5. Place battery tray back on
6. Piece back together airbox with mounting bolts
7. Place battery back onto place with its rear mounting bolt
Sources:
[1]. http://forum.2gn.org
[2]. http://www.justanswer.com/dodge/2i4xz-c ... -neon.html
[3]. https://www.youtube.com/watch?v=sgGgs9FEnto
[4]. https://www.youtube.com/watch?v=I8teB16 ... &index=101