Also be sure to have the basics:

1. Good ignition. (fresh spark plugs, good shape wires, new or clean distributor cap and rotor and a good coil)

2. Make sure that aircleaner is clean. K/N have good washable permanent filters.

Bad ignition and bad breathability both causes bad milage.

Here's what to expect in the C101 connector. Also I included a pic of the 6 brown with white tracer wires that need to be soldered together. Follow cruiser54 write up and you will be fine.

I get about 15mpg around town in my 2000

I'm going to clean the c101 connector... Can someone elaborate on the wires that need to be soldered together?.... What are they for? I haven't taken it apart yet, but it's coming soon.
I'm also going to add ground straps and replace the braided strap with something more substantial.

I get about 15 in town and I haven't had the opportunity to see what sort of highway mpg it gets yet.

95 sport--about 10mpg,delivering mail.55 route miles,not counting to and from work.

Are you doing a complete ground refreshing and cable addition per my write-up? If so, all that info is there including part numbers from Napa.

What wires are you thinking of soldering?

Sensor ground circuit connectors are a good idea. You can also just solder ALL the C101 wires together. Or, if your Jeep hasn't had the CPS bypass, just solder the CPS wires at the C101.

Just looking for info about the brown wires that were mentioned to solder.
I don't know anything about a CPS bypass.
And yes, I'm going to go through all the grounds.

Here's the test:
Cruiser’s Renix Sensor Ground Test
　
This sensor ground circuit affects the CTS, TPS, IAT, MAP, ECU and diagnostic connector grounds. It’s very important and not something to overlook in diagnosing your Renix Jeep as it is common for the harnesses to have poor crimps causing poor grounds. If any or all of the sensors do not have a good ground, the signal the ECU receives from these sensors is inaccurate.
Set your meter to measure Ohms. Be sure the key is in the OFF position. Using the positive (red) lead of your ohmmeter, probe the B terminal of the flat 3 wire connector of the TPS . The letters are embossed on the connector itself.
Touch the black lead of your meter to the negative battery post. Wiggle the wiring harness where it runs parallel to the valve cover and also near the MAP sensor mounted on the firewall. If you have an 87 or 88 with the C101 connector mounted on the firewall above the brake booster, wiggle it, too.
You want to see as close to 0 ohms of resistance as possible. And when wiggling the harnesses/connectors the resistance value should stay low. If there is a variance in the values when wiggling the wires, you have a poor crimp/connection in the wiring harness or a poor ground at the engine dipstick tube stud. On 87 and 88 models, you could have a poor connection at the C101 connector as well.
Revised 06/12/2012

Here's the procedure:

Find your Intake Air Temp sensor. It's the sensor just to the rear of the throttle body, has 2 wires, and screws into the intake manifold.
Where it's connector plugs into the harness you will see that one of the wires on the harness side　is brown with a white stripe. Follow the brown with white stripe wire back into the harness. You'll have to open up the split-loom plastic sheathing to follow it. It will come to a splice with 2 other brown with white wires with duct tape over them. They're from the TPS and the CTS. The 3 wires will be　 spliced to a single wire headed toward the C101 connector if you have an 87 or 88. If you have an 89 or 90, you do not have the C101 bulkhead connector.
　
Now go to the MAP sensor. Follow the brown with white wire into the harness from there. You will find a splice with 2 more brown with white wires with duct tape over them. At the splice you will find the 3 wires connected to a single brown with white wire going toward the C101, or just along the firewall towards the engine if you have an 89 or 90. Along with the MAP sensor that you traced, they are the ECU sensor ground port and the diagnostic connector on the passenger inner fender.
　
You now have 2 sets of 3 brown with white wires, one near the firewall and one near the engine.
　
Cut the splices out of each set of wires eliminating not only the crappy factory splices, but also the single wire between them. Bring both sets of 3 wires together. Solder the 2 sets of wires together and insulate them properly with tape or shrink tubing.
　
Zip-tie up your new sensor loom to allow for engine movement.　I prefer to cover it with some new split-loom or wrap it neatly with electrical tape when done.
　
　
Revised 03-09-12