Here's your options: (I have emissions here in arizona and i passed.)
1. swap out all the cats from the explorer to the ranger(they do infact fit) as well as the o2 sensors
2. Keep all your EGR and vaccum lines hooked up
3. Id do torque monster headers for increased Horse Power and MPG
4. Go with a MAC intake system to help the motor breath(also better MPG)
5. Buy yourself a SCT XCAL3 and have a tune made for it disabling PATS(couple tuners on here will help you with that) or just swap out the PATS from the explorer to your ranger(good luck on wiring)
6. Is it AWD or 2wd? If its AWD then you can just swap tranny, transfercase and driveshafts straight over. If its a 2wd you will need to buy an Advance Adapter kit(5in kit) and have your transmission taken down to have the new output shaft put in. You will need to have your driveshafts lengthen shortened accordingly with that kit. There is also other routes to take here for transfer case's but BOB would know more about that.
7. You will need to have a exhaust shop weld you up a new cat back exhaust setup
8. I think thats it off the top of my head but this is what you'll need in a nutshell
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