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How long do late model XJ cats last?

R

rumblebelly

NAXJA Forum User
Location
FT COLLINS, CO
I'm thinking about replacing my stock muffler. It has this weird droning sound inside the cab gets on my nerves. However, I really don't wanna do it if the cat will fail later. I had a cat on my old 88 XJ and it failed at around 110K so I just replaced the whole exhaust at once. My 2000 has about 73K on it. Does the new system last longer than earlier models?
 
Ludakris said:
cats usually last longer than dogs.
Click to expand...

I knew it was coming....:jester: My 01 has 83+K on it and the cat and muffler aint even rusted. Judging from the wall thickness of the stock system, it'll be around quite a while, and I live where they DO put salt on the road.
 
Federal warranty is 8yr/80,000miles - They have to last that long, or the manufacture MUST replace it, for free. I wouldn't go replacing the cat @ 73K. Also, is your current muffler causing the droning sound? I'm not trying to second guess you, just want to make sure that the muffler is the cause of it...

*The newer XJ's have an alloy exhaust system - it will last much longer than the one that was on your '88.

*My '97 XJ has 170K on it - Exhaust is all original - Except for the manifold....

Will.
 
xjwillyb said:
Federal warranty is 8yr/80,000miles - Also, is your current muffler causing the droning sound? I'm not trying to second guess you, just want to make sure that the muffler is the cause of it...


Will.
Click to expand...

I honestly don't know for sure but it's the only thing I can think of. It does it even when the vehicle is stationary so it aint the pig and I know it's not coming from the fuel pump. Actually, it sounds loudest from inside...right above where the tail pipe bends up over the axle on the right side. After the muffler guy looked at it and listened to it, he said replacing the muffler might not take care of the drone sound. He said it's a "resonance" sound which might be caused by something else vibrating.

It occurs at 1700, 2500, and 3000 rpms. Jeep even put out a TSB on it which says to replace the muffler and tail pipe if nothing else is loose. I can't find anything loose either.

If it is the muffler, would Jeep be responsible for the replacement? Could there be something loose inside the muffler and would that qualify for a failure?...doubt it though but hey, you never know.
 
Last edited:
The next time that you hear this droning sound, lightly lift the 4x4 selector lever up about 1/3 of an inch.

Just a hunch...
 
I experience this same mild drone sound at the RPM's that were listed above. I too figured it was just a muffler/exhaust issue. I'll be curious to try this "lifting of the tcase lever a bit".

If lift the lever has control over it... what is the remedy?
 
jdraylob2002 said:
I experience this same mild drone sound at the RPM's that were listed above. I too figured it was just a muffler/exhaust issue. I'll be curious to try this "lifting of the tcase lever a bit".

If lift the lever has control over it... what is the remedy?
Click to expand...

Cool, now I can tell my better half that I'm not nuts. She claims it isn't very loud. I guess it's hard to justify spending a $100-150 to try to get rid of that sound but sometimes it gets on my nerves, especially when it starts to interfere with the stereo (nothing should ruin my tunes man!).

Is BudTX implying that the exhaust is rubbing up against the t-case or tranny? The last time I looked, the exhaust looked pretty far from everything.
 
I would guess that BudTX is referring to a vib noise coming from the tcase..

But it sure sounds like it comes from further back... and on the passenger side where the exhaust runs.
 
I have a 94' with 173k and it still has the stock cat and even my 87' with 325k has the stock cat and I live in the salt belt of NY! I had the same noise your describing on my 94' and found that where the exhaust went over the rear axle it was accually vibrating against the floor. It hasnt done it since I replaced the muffler and tail pipe. Good luck
 
I've got 113,000 on my XJ. Just passed the smog test with no problem. Unless your engine is running rich for some reason or your oxygen sensor goes bad, the cat should last for many years.

MAP
 
My 98 has over 250,000mi on it, still stock exhaust...
 
I have a new exhaust (cat. muff. t-pipe, hanger,etc)...."drone-ier" than ever, I just live with it, checked everything for vibrations...all seems good....loud in cab, quiet as a mouse outside. 90" XJ 4.0.
 
dizzymac said:
I have a new exhaust (cat. muff. t-pipe, hanger,etc)...."drone-ier" than ever, I just live with it, checked everything for vibrations...all seems good....loud in cab, quiet as a mouse outside. 90" XJ 4.0.
Click to expand...

On this note.. anyone have knowledge of a good quality Quiet exhaust system?

I might just change the gears and stay stock on the intake and exhaust. Go up to 3.73's or so...
 
The Tcase lever bushing can vibrate and cause a drone inside the cab at certain RPMs. Mine does it at or close to idle. It sounds almost like a helicopter flying by. Removing the slop in the Tcase handle eliminates the vibe.
 
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