More than a few Questions for my 2000 explorer sport 4.0L

[DeuceHarris519]

1) The door panel number pad key-code entry? Reprogrammable?
2) Cheapest key fob for wireless entry?
3) Recommended Battery, Exhaust, Intake, plugs and any other components I should consider replacing. Quality and lower priced as well.
4) I will have two children in car seats permanently residing in the back until they grow out. Any safety concerns or upgrades I should consider to better make this vehicle a more safe environment while precious cargo is on board.
5) It is 4x4 is there anything I should know about it getting stuck in 4H 4L or any other things I should know about how to avoid any problems. I twmporarily leased a 1998 explorer 4x4 awhile back and had issues.
6) any loopholes or neat tricks I could learn.

To give you a better understanding I purchased used. One previous owner, didnt get sold from manufacturer until 2003. Bounced around 3 locations before being sold to mature older woman who passed away shortly before me buying it. She was reluctant enough to only put on 124,000KM On it since her ownership. My budget for parts is $1500 I have $500 aside for labour.

 

[bobflood]

1) The door panel number pad key-code entry? Reprogrammable? Yes - look in owners manual for process.
2) Cheapest key fob for wireless entry? Search eBay
3) Recommended Battery, Exhaust, Intake, plugs and any other components I should consider replacing. Quality and lower priced as well. Air filter, oil and filter, fuel filter; Motorcraft where possible; avoid Bosch plugs.
4) I will have two children in car seats permanently residing in the back until they grow out. Any safety concerns or upgrades I should consider to better make this vehicle a more safe environment while precious cargo is on board.
5) It is 4x4 is there anything I should know about it getting stuck in 4H 4L or any other things I should know about how to avoid any problems. I twmporarily leased a 1998 explorer 4x4 awhile back and had issues.
6) any loopholes or neat tricks I could learn.

To give you a better understanding I purchased used. One previous owner, didnt get sold from manufacturer until 2003. Bounced around 3 locations before being sold to mature older woman who passed away shortly before me buying it. She was reluctant enough to only put on 124,000KM On it since her ownership. My budget for parts is $1500 I have $500 aside for labour.

 

[AppleWood]

3.)Truck weighs in @ approx. 4K pounds, should be safe in anything other than head-on with locomotive.

4.)It's a 10+year-old mechanical device, subject to wear and tear. Get ya' a factory service manual and follow preventative maintenance outlined...