Callsign-Rio

Hey everyone!
I'm new around here as well a bit of a newbie to Cherokees, so I have a few questions.
First off, I own a 94' XJ Sport, 4door. Minus my own modifications here and there, the thing is fairly stock, but I don't want it to stay that way.

More recently, whenever the conditions here get wet, I come to a stop and it takes a moment for my rear brakes to engage, and when they do, there's a very loud thump like there's slack in the drivetrain and my engine's fighting the brakes.

My brakes seem extremely weak. Every now and then, they'll have a bit more strength and pedal resistance, but more times than not, I could lay the pedal to the floor and the tires won't lock up on pavement. I bled them thru but still have to much coasting to my liking. They're non-ABS btw.

My mileage stinks. When we got it, there was a crack in the manifold which we fixed, and then the O2 sensor was replaced after my check engine light kept coming on. Due to the fact that most O2 sensors are a butt load of money, for me at least, I got a $15 off of Amazon. The connector didn't fit quite like it should and I'm only getting less than 200 on a full tank. I replaced the fuel filter, ran injector cleaner and 91 through it once. Didn't change a thing.

Synthetic oil: blend or full?
My brother had a 97 4.0L TJ a while back before a lady in a Lexus rear ended him at a stop light after his battery died (bad alternator). He presumably put a full synthetic in it and shortly after the oil sensor got all screwed up.
A buddy of mine has a 01' XJ 4.0L and ribs full synthetic without a problem.
I've got 191k on mine and want it to last me long after now. What should I use?
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I've got plenty of questions but for now I think this will be enough. Thanks guys!

Also, anybody got some recommendations? Right now, it's my only car and would like to prolong it's life, but if anything, I want to turn it into a trail runner. I'm not really one for crawling or mudding. The drivetrain is stock all around, Dana 30 in front, Chrysler 8.25 in the rear, though I don't know what gearing ratios or spline numbers. Can someone explain these to me, or tell me where I can find answers?

MonacaYankee

brakes. Rebuild the drum system or convert to disc brakes. Look into converting the master and brake booster to a 95 or 96 setup for more braking power.

o2 sensor. It is recommended to get a NTK brand o2 sensor. They are around $30.

Oil. Run whatever factory spec oil you want. Don't run fram filters they are junk.

Gears. You most likely have 3.55s. Check the metal tag on the axle if it is there. It should be on one of the diff cover bolts.

Callsign-Rio

Thanks for the info.

What do you mean by 95 or 96 for the master cylinder? And the only disk conversions I've seen just change the rotor from a drum to a disk but still have the drum pad setup.

I forgot to mention that the diagnostics show the mixture going berserk, flashing between lean, center and rich, even after I replaced sensor. Could it be I just got a bum knockoff?
Where can I find a NTK O2 that cheap?

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EZEARL

$30.79= shipping:
http://www.rockauto.com/en/moreinfo....180213&jsn=385

Only pads on the conversion are for the parking brake:
https://www.cherokeeforum.com/f71/di...on-kit-159484/

Callsign-Rio

Thanks!
I don't really have money for a disk conversion, but thanks for the links.
I'll definitely look at the sensor.

cruiser54

Remove the brake drums and inspect the brakes.

If they're in good shape, manually adjust them.

Callsign-Rio

I recently checked them, there's still a good few millimeters on them.
Adjust them? How do you do that?