Bank 1 too lean and multiple misfire
Thread Starter
CF Veteran
Joined: Feb 2011
Posts: 3,500
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From: Long Beach, Ca
Year: 2000
Model: Cherokee
Engine: 4.0 I6
Thats right, I'm pretty much screwed. New oem sensors are on order at the stealership, really hoping this solves the problem. And I might as well get the banks headers while I'm at it
Thread Starter
CF Veteran
Joined: Feb 2011
Posts: 3,500
Likes: 0
From: Long Beach, Ca
Year: 2000
Model: Cherokee
Engine: 4.0 I6
Thread Starter
CF Veteran
Joined: Feb 2011
Posts: 3,500
Likes: 0
From: Long Beach, Ca
Year: 2000
Model: Cherokee
Engine: 4.0 I6
Ok I'm back. Brand new Mopar o2 sensors (all 4) and still the same problems. Multiple missfire on cylinders 4 and 5 this morning. I think I'm just going to jump right in to replacing the head as this xj had been overheated by the previous owner about 100,000 miles ago. I'll come back after the head is replaced but it's going to take a while to get the money and time.
CF Veteran
Joined: Dec 2010
Posts: 1,700
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From: S.Jersey
Year: 1999
Model: Cherokee
Engine: 4.0
I don't recall if u mentioned the over heat issue, so that def could be it.
But maybe u should ohm out the coil packs first before condeming the head.
With the over heated issue I would think it would have shown its self well before 100k. Not to sure though. Def test the coil pack first. Wish I had noticed u had a 2000, I would had sugested that first. Sorry buddy.
But maybe u should ohm out the coil packs first before condeming the head.
With the over heated issue I would think it would have shown its self well before 100k. Not to sure though. Def test the coil pack first. Wish I had noticed u had a 2000, I would had sugested that first. Sorry buddy.
Thread Starter
CF Veteran
Joined: Feb 2011
Posts: 3,500
Likes: 0
From: Long Beach, Ca
Year: 2000
Model: Cherokee
Engine: 4.0 I6
I don't recall if u mentioned the over heat issue, so that def could be it.
But maybe u should ohm out the coil packs first before condeming the head.
With the over heated issue I would think it would have shown its self well before 100k. Not to sure though. Def test the coil pack first. Wish I had noticed u had a 2000, I would had sugested that first. Sorry buddy.
But maybe u should ohm out the coil packs first before condeming the head.
With the over heated issue I would think it would have shown its self well before 100k. Not to sure though. Def test the coil pack first. Wish I had noticed u had a 2000, I would had sugested that first. Sorry buddy.
Senior Member
Joined: Apr 2012
Posts: 578
Likes: 4
From: Ocean, New Jersey
Year: 2000
Model: Cherokee
Engine: 4.0
Coil rails rarely fail and your symptoms don't sound like a faulty coil pack. Your money your choice but if it were me I'd check local JY for used cats.
Thread Starter
CF Veteran
Joined: Feb 2011
Posts: 3,500
Likes: 0
From: Long Beach, Ca
Year: 2000
Model: Cherokee
Engine: 4.0 I6
CF Veteran
Joined: Dec 2010
Posts: 1,700
Likes: 0
From: S.Jersey
Year: 1999
Model: Cherokee
Engine: 4.0
Coil packs can most def fail. Older stlye ignition systems with a distributor and a single coil have a longer life span than any coil pack or coil on ignition system i've seen.
You could also have a heat soak issue with on of the injectors. there was tsb issued for 00-01 cherokees for heat soak issues . you might want to see if you have any recalls of this nature.
Its a missfire code. meaning quite possibly that one or more the coils is not firing. I would listen to ur mech.
btw no jy will sell you a cat. Its a federal law that they can't. if they are its illegal in any state.
Last edited by OEJ; Mar 31, 2013 at 05:00 PM.
Thread Starter
CF Veteran
Joined: Feb 2011
Posts: 3,500
Likes: 0
From: Long Beach, Ca
Year: 2000
Model: Cherokee
Engine: 4.0 I6
I'm going to try new coil and spark plugs tomorrow. The rough idle and exhaust smell is intermittent which is leaving me to believe that it might not be the head. If a new coil doesn't fix thus I'm just going to get a rebuilt engine from ATK. If I'm going to spend hundreds on a new head plus install I might as well just get s fresh engine. I'll update you guys in a few days if the new coil works or not.
One thing I've learned about owning an xj, it's good to have a second car lol
One thing I've learned about owning an xj, it's good to have a second car lol
Thread Starter
CF Veteran
Joined: Feb 2011
Posts: 3,500
Likes: 0
From: Long Beach, Ca
Year: 2000
Model: Cherokee
Engine: 4.0 I6
I completely disagree with this statement. No disrespect intended Kalali.
Coil packs can most def fail. Older stlye ignition systems with a distributor and a single coil have a longer life span than any coil pack or coil on ignition system i've seen.
You could also have a heat soak issue with on of the injectors. there was tsb issued for 00-01 cherokees for heat soak issues . you might want to see if you have any recalls of this nature.
Its a missfire code. meaning quite possibly that one or more the coils is not firing. I would listen to ur mech.
btw no jy will sell you a cat. Its a federal law that they can't. if they are its illegal in any state.


