Have a few questions.... I got my Jeep a couple weeks ago, had a dealer find it at an auction, was looking for something to deliver mail out of, I told him to make sure everything was good with it. It supposedly had a cat converter prob so he arbitrated it for a lower price to fix it for me. He said it was just an o2 sensor code once he got it back to his lot but he cleared the code and it was not coming back on and it was not running like it needed a converter. When I went to pick it up it threw the code again, P0431 / warm up catalyst efficiency below threshold bank 2, He said it might just be dirty because it was used as a mail car on dusty gravel roads and to try to take the sensor out and see if it is dirty, is that possible? Could dirt get in there and make them malfunction? ( I did not see this code on the code chart here, but found a link with video showing it could be loose exhaust ) Anyway I hadn't got to that yet as I have been working and it isn't running too bad, have noticed a little loss of power at highway speeds going up hill and it will idle a little funny every now then when I am stopped at a mail box. Tonight I ran a code check through the ignition and it is showing another code also P0456 along with the P0431 anyway in lieu of fixing the converter/ 02 sensor he said he fixed the sway bar and and few things to pass inspection, Oh did I mention I'm a girl and mechanics etc. like to screw me over... But I took a dude form work and he didn't say that wasn't an even trade off and the dealer is my bosses friend, so I figured all was good, at Orileys today the guy there said the sway bar would be about half the cost of a converter so maybe I did get screwed... I am far from a mechanic but figure I can check for a loose exhaust while I am putting a new connector on the wire that runs to my starter that broke off today, I actually found the problem myself LOL Hey I was proud, as I said I am no mechanic, and a girl, well an old girl...

Anyway, if the exhaust is causing the P0431 code do you think that it could also be causing the P0456 code? And could a dirty sensor cause the code?

I also noticed a drip by chance and when I got it home and searched under the hood I found this to be a little wet, so a small leak in the coolant lines? how bad is that?



While under there noticed this had some oily residue couldn't tell how it got there... opinions?



And then after going to see which axle I had because I was reading the TJ/LJ axle Identification thread I found this, haven't noticed any spots in driveway till I found this tonight, so assuming it just started. What is your opinion/advice for this?



I've been reading this forum and looking up things I didn't understand, and trying to learn about my wrangler and what things I might be able to do myself (tired of mechanics pulling an engine fan relay and telling me I need a new engine fan and it would cost $500) yeah that really happened, But I found it out myself hoping maybe it was just a blown fuse and checking the fuse box. So, I am extremely mechanically challenged but not a complete idiot. Oh and I can change a tire with the best of them! lol

So, these are my troubles, for today, any advice or info and links for how to's would be greatly appreciated!

Oh and I wanted to say how impressed I am with this forum and all the friendly people and the vast amount of knowledge here! I've come across so many awesome threads, seen some bad ass jeeps and am amazed at what you can do with your jeep in your own garage! Really wish you all were my next door neighbors!

No a dusty environment will not affect a O2 sensor.
if the moisture is on the silver lines, those are a/c lines, and that is normal condensation from air conditioner use.
Is your leak coming from the bottom at the cover? or the front of the rear by the yoke? If its just the cover, would be a good time to change the oil on both rears and sealing them back up will solve your leak. If it is up front the differential, then the pinion seal must be replaced by a competent mechanic. because if someone overtightens that yoke, you will be looking to replace or rebuild the whole differential assy.

PO456
https://www.wranglerforum.com/f210/p0456-code-15939.html

PO431
https://www.wranglerforum.com/f210/po431-code-79852.html

I threw lean codes and o2 codes. Replaced all 4 o2's and one came back. Replacing the manifold gasket fixed it right up. Right before emissions testing .. What a pain in the ass.
With 150k i went and replaced the coil rail too.
Jeep ran real nice before i sold it.

Ok got back under there and this is from the other side

So it looks like I need a new pinion seal... Any idea what this should cost?

Your differential cover and pinion seal are leaking. If the pinion seal is just wet, I wouldn't worry about it. You could go indefinitely with a small pinion seal leak, it won't hurt anything. Just check to make sure your gear oil is full every once in a while.

The differential cover leaking is also not a big problem but if its leaving spots on your driveway or garage you may want to fix it. Its up to you. If you leave it, again just check your oil every once in a while.

If you want to fix the differential cover just order a Lube Locker Gasket for your axle, remove the bolts that hold the cover on, let the oil drain out, scrape the old glue off the cover and axle, put the new gasket on, bolt it back on, and fill the axle up with new oil. It shouldn't take more than 30 minutes or so.

The cover is not leaking, the pinion seal is, and running down the diff and dripping off the lowest point, which from the front view looks like the cover is leaking. But if the pinion seal is leaking enough to run down the diff and make a spot on the ground would this not be a serious leak?

Oops, I didn't look at your pictures close enough. Personally I would probably just leave it but that's just me. Check your oil level to make sure you haven't leaked a bunch out. They aren't that hard to replace or expensive if you do want to change it out. Pull driveshaft, unbolt the yoke, change the seal, bolt the yoke back on, and reattach the driveshaft.

Do you have any driveline vibrations by chance?

If your rear end is a Dana 44 there is no crush washer with the seal. The replacement is easy except for the very high torque to get the nut off and on. I am a big guy and have trouble with that. It really needs to be up on a lift to get that sort of leverage unless you know what you are doing. Perhaps a friend who has done this before? Or a local club?

If your rear is a Dana 35 then it is more complicated as *I think* there is a crush fitting and you have to set the drag on the axle to like 10 inch pounds. Again, *I think* this is the case. DO NOT GO BY WHAT I HAVE SAID HERE. Just use my words as a guide to your research.

Do you have the Factory Service Manual (FSM) for your TJ? If not, go to Jeeps Limited - About and sign up. He has a repository of FSMs and parts lists for many of the TJ years. If you register you can download the stuff for free. A hard copy new from the dealer is now like $180 or so. So get the free PDF. It is well over a thousand pages and someone did a great job of indexing it for searches.

Good luck!

The crush sleeve is only on the front Dana 30, not the rear 35 or 44

Thanks for that clarification. I did not know about the D35. I need to read my FSM on the two rear axle choices. I was pretty sure the 44 did *not* have one, though. Adios!

When I got her the dealer said she kind of vibrates or rides rough like a jeep at hwy speeds... My first jeep so figured it was normal, and after reading some threads others were describing the same thing. I also figured it was my tires helping the rough vibratey ride...Had 2 tire plugs in the first two days I had her (not by choice as plugs break through the steel belts and make it ride crappy) and the tires were rocked checked from being a previous mail jeep, but then I noticed a different vibration for a couple days real light, would vibrate for a couple seconds and then be ok for a couple seconds and would do this my entire hwy drive to and from work, I did not know where it was coming from. Then I had a low tire and figured that what had been causing this new vibration, I put on my spare till I could get my tire patched and I did not notice it on my drive home after, but was not paying close attention, and it had been a real light vibration. I have not driven since that.

So what would cause vibrations in the driveline?

The reason I asked is pinion bearings and seals can go out because of driveshaft vibrations if left over a long period of time.

If your jeep is lifted the vibration could be from an excessive driveshaft angle. If it isn't, a bad ujoint, front CV ball, or bent/unbalanced driveshaft can cause vibrations.

Because you have had tire problems the first thing I would do is get all 4 tires balanced.

Well a quick look by my mechanic and I have bad u joints and seals, waiting for an open lift to give her a good going over. Wish me luck. hope there's nothing else wrong!