Diagnosing O2 sensor related codes

ebay007

ebay007

New Member
Joined
Mar 20, 2019
Messages
22
Location
Australia
Hi folks.
I was hoping to get some opinions on a problem I have as I could not find a thread that would directly answer it.

A little background- 3 months ego I bought a 2005 4.0L manual TJ with 125,000Km (=78,000 miles).
It has no obvious mods or upgrades besides 31' tires and a roo bar (I'm in Australia 🆒)

So, my problem is getting p2098 and p2096 codes, but it only happens after a long drive on the highway. Lets say after about 1 hour.
I get no other codes and the Jeep drives just fine. It seems like nothing else is wrong.
When I clear the codes they do go away and not come back unless I again go for a long highway drive.

From reading I understand these two codes are about the downstream sensors (Bank 1 and 2 in my case) reporting lean exhaust mixture.

Also from reading, I learnt the following:
  1. This is relatively common, and it's ok to reset the codes and continue.
  2. There is a TSB specifically for the 2005 model.

How can I know if my ECU was flashed with the firmware that should have fixed it?
How do I know if this is because of the ECU bug or because of a real problem?
Is there a way to test the o2 sensors to see if they are faulty or if the problem is elsewhere?

My situation is that I'm tight on money and not many parts are available where i'm at.
The upside is that I'm very technical and will invest the time to investigate the problem so that I don't just replace parts.

I would really appreciate any help.
Thanks,
Matan.
 
  • Like
Reactions: HardSell and Chris
  • Like
Reactions: Chris
ebay007 said:
How can I know if my ECU was flashed with the firmware that should have fixed it?
Click to expand...

Short of taking it to a dealer and having them check out the ECU firmware for you, I don't think there is a way of knowing.

ebay007 said:
How do I know if this is because of the ECU bug or because of a real problem?
Click to expand...

No real way of knowing, but I can tell you this. O2 sensors are a normal wear-and-tear maintenance item. You should be replacing ALL OF THEM (not just the bad ones) around every 80k miles or so if you want your engine to be running optimally. This means that you shouldn't want until the check engine lights come on, just simply replace all the sensors at once, and then you won't have to worry about it for quite a while. Again, it's a typical maintenance item, just like changing your tires.

ebay007 said:
Is there a way to test the o2 sensors to see if they are faulty or if the problem is elsewhere?
Click to expand...

I believe there is a way to test the O2 sensors outlined in the FSM, which you can download for free here:
Jeep Wrangler TJ Factory Service Manuals (FSM) & Technical Documentation

Still, if you don't know the last time all your O2 sensors were changed and your TJ has higher miles, you need to change ALL OF THEM.
 
Thanks for bringing RockAuto to my attention, turned out to be cheaper then amazon by 40$!
Ordered all 4 sensors and the socket.
Will update after replacement for future readers.

Thanks for the help.
 
  • Like
Reactions: HardSell and Steel City 06
ebay007 said:
Hi folks.
I was hoping to get some opinions on a problem I have as I could not find a thread that would directly answer it.

A little background- 3 months ego I bought a 2005 4.0L manual TJ with 125,000Km (=78,000 miles).
It has no obvious mods or upgrades besides 31' tires and a roo bar (I'm in Australia 🆒)

So, my problem is getting p2098 and p2096 codes, but it only happens after a long drive on the highway. Lets say after about 1 hour.
I get no other codes and the Jeep drives just fine. It seems like nothing else is wrong.
When I clear the codes they do go away and not come back unless I again go for a long highway drive.

From reading I understand these two codes are about the downstream sensors (Bank 1 and 2 in my case) reporting lean exhaust mixture.

Also from reading, I learnt the following:
  1. This is relatively common, and it's ok to reset the codes and continue.
  2. There is a TSB specifically for the 2005 model.
How can I know if my ECU was flashed with the firmware that should have fixed it?
How do I know if this is because of the ECU bug or because of a real problem?
Is there a way to test the o2 sensors to see if they are faulty or if the problem is elsewhere?

My situation is that I'm tight on money and not many parts are available where i'm at.
The upside is that I'm very technical and will invest the time to investigate the problem so that I don't just replace parts.

I would really appreciate any help.
Thanks,
Matan.
Click to expand...

Hi there,

I have the same problem as you and am still in the process in sorting it out. But thought I would let you know that I took my 05 Wrangler to a dealer for a ECU update and when they plugged it in there was no update available. I'm going to try and replace all my 02 sensors and see if that helps (previously just replaced the one with the specific error code). Fingers crossed.
 
The sensors arrived pretty quickly from RockAuto so I will replace them this weekend.

Also arrived is a OBDII scanner which works really well!
http://rover.ebay.com/rover/1/711-5...0001&campid=5337789113&icep_item=251488093341

It shows the following codes:
86260




It also allows me to see live voltage data from the sensors, but i'm not actually sure what I should look for
 
This site contains affiliate links for which Jeep Wrangler TJ Forum may be compensated.
When I was at Jeep they printed out the diagnostic step by step for me to pass onto a mechanic. Unfortunately I don't have scan tool to test it but you might have more luck with your OBDII scanner. It lists the voltages of the O2 sensors in there. Hope it helps!
 

Attachments

  • Jeep P2096 and P2098 Codes.pdf
    242.8 KB · Views: 386
Well, replacing all 4 sensors does not seem to help so far.
It still throws p2098 and p2096 whenever I go on a long drive of 1+ hours or so...
 
Guys...be dead sure 4 the bolts are snug at the cats..dead sure..,or it sucks in cold air and confuses the computer that’s reading upstream and downstream .
 
  • Like
Reactions: HardSell
ebay007 said:
My situation is that I'm tight on money
Click to expand...
That's exactly why I'm driving a TJR rather than a $50,000 JLR. Over in the JL forum, seems like they have even more problems than we do. LOL! Codes in mine come and go. I've had a dozen codes come and go since I bought mine last Feb. Jeep runs fine & gets decent MPG for a Rubicon 6sp with 33s, (14-17). My stolen 33 year old 285k XJ (31s-Dana 44+ ARBs) got 19-21; so much for technical advances! Hate trying to fix things which are not broken because of lousy computers we don't need. So, I'll be chasing down the old 2098 code now. 15 months till emissions due... will post further when something empirical happens.
 
Top Bottom
Back