I was getting ready to purchase the upstream for my 98 2.5 that I just acquired. It has a Japser sticker so I assume not the original engine. The above list has a 98 specific sensor. How would I tell what year engine I have? Any insight is appropriated.What are Bank 1, Bank 2, etc.?
Since this question pops up from time-to-time, here's an easy to follow diagram that illustrates what they mean when your OBDII code scanner (or manual) tells you something like "O2 sensor, Bank 1, Sensor 2":
View attachment 12208
What does upstream and downstream mean?
Simple, upstream means the O2 sensor is "upstream" of the catalytic convertors, meaning before the catalytic convertors. Downstream means the O2 sensor is "downstream" of the catalytic convertors, meaning after the catalytic convertors.
What brand of O2 sensors should I use for replacements?
Pay close attention to this one so you can do it once and do it right! The Jeep Wrangler TJ is extremely sensitive to all oxygen sensors other than NGK / NTK. Bosch O2 sensors and all the others (including the crappy Chinese brands you'll buy at your local auto part store) are very well documented as not working properly with our TJs. In other words, you plug them in and you assume all is well, until you notice your check engine light isn't going away. This is almost always due to the fact that you didn't use an NGK / NTK replacement O2 sensor.
Okay, so why don't other sensors (i.e. Bosch) work on our Jeeps?
Glad you asked! Check out this video for a detailed explanation of why other brands of O2 sensors don't work on our TJs:
So which O2 sensors do I need?
I'm going to break down which sensors you need based off what year your TJ is. The part numbers (and information) below were taken directly from the NGK website, so you can assure it is 100% accurate (even double checked each individual year and model before writing this thread).
4 Cylinder Engines1997-2000NGK #23506 - Bank 1, Sensor 1 (Upstream)NGK #23151 - Bank 1, Sensor 1 (Upstream) (1998 ONLY)NGK #23099 - Bank 1, Sensor 2 (Downstream)2001-2004NGK #23138 - Bank 1, Sensor 1 (Upstream)NGK #23141 - Bank 1, Sensor 2 (Downstream)2005-2006NGK #23159 - Bank 1, Sensor 1 (Upstream)NGK #23159 - Bank 1, Sensor 2 (Downstream)6 Cylinder Engines1997-1999NGK #23151 - Bank 1, Sensor 1 (Upstream)NGK #23099 - Bank 1, Sensor 2 (Downstream)2000NGK #23122 - Bank 1, Sensor 1 (Upstream)NGK #23506 - Bank 2, Sensor 1 (Upstream)NGK #23099 - Bank 1, Sensor 2 (Downstream)NGK #23099 - Bank 2, Sensor 2 (Downstream)2001-2003NGK #23139 - Bank 1, Sensor 1 (Upstream)NGK #23138 - Bank 2, Sensor 1 (Upstream)NGK #23142 - Bank 1, Sensor 2 (Downstream)NGK #23141 - Bank 2, Sensor 2 (Downstream)2004NGK #23137 - Bank 1, Sensor 1 (Upstream)NGK #23135 - Bank 2, Sensor 1 (Upstream)NGK #23132 - Bank 1, Sensor 2 (Downstream)NGK #23531 - Bank 2, Sensor 2 (Downstream)2005-2006NGK #23018 - Bank 1, Sensor 1 (Upstream)NGK #23160 - Bank 2, Sensor 1 (Upstream)NGK #23159 - Bank 1, Sensor 2 (Downstream)NGK #23158 - Bank 2, Sensor 2 (Downstream)Misc Installation Notes
When installing new O2 sensors, be certain to use some anti-seize on the threads of the new O2 sensors! This is important, and will save you a huge headache should you ever need to remove them in the future.
In addition, a O2 sensor socket will greatly aide in the installation and removal of O2 sensors. I recommend this one.
Not sure how you can tell the year just from the engine. You may need to post a new thread as I know nothing about the 4 cylinders.I was getting ready to purchase the upstream for my 98 2.5 that I just acquired. It has a Japser sticker so I assume not the original engine. The above list has a 98 specific sensor. How would I tell what year engine I have? Any insight is appropriated.
It has a Japser sticker so I assume not the original engine.
Thanks! I assume I will use the year of the engine as opposed to the year of the CPU?Find the serial number on the engine then call Jasper and ask them.
Thanks! I assume I will use the year of the engine as opposed to the year of the CPU?
I'd start by clearing it and then seeing if it comes back. Could always be a fluke.@Chris this thread is invaluable! Along the same lines, has anyone had an issue with a CEL (p0421) coming on after changing plugs? I just put in a fresh batch of Autolite XP Iridiums after a CEL and a limp home (P0300). The rig drove like a charm for about 2 days, then threw me the code again.
I didn’t even think about that...I’ve got 92k on the rig now and I’m leaning towards bad sensors (I already ordered some) but I’ll clear it and see how it goes!I'd start by clearing it and then seeing if it comes back. Could always be a fluke.
The sensors definitely do go bad and to be replaced...it’s definitely not a frequent thing.So My CEL came on and the codes were for both upstream o2,s, I cleared the code while waiting for new o2,s to get to OZ from Rock Auto but the CEL has not come back and its not using excessive gas. Do they actually need changing or does this just happen sometimes?
Cheers
And it’s also best to replace the sensors in pairs (according to RockAuto/OEM). Plus they are kind of annoying to replace so you might as well kill 2 birds with one stone. I prefer using an O2 sensor socket as well.So My CEL came on and the codes were for both upstream o2,s, I cleared the code while waiting for new o2,s to get to OZ from Rock Auto but the CEL has not come back and its not using excessive gas. Do they actually need changing or does this just happen sometimes?
Cheers
Not sure this was posted, I have an early 2000 TJ I purchased in December 1999, contrary to this chart, some early 2000 6-cylinders may only have 2 sensors, upstream/downstream of the catalytic converter.What are Bank 1, Bank 2, etc.?
Since this question pops up from time-to-time, here's an easy to follow diagram that illustrates what they mean when your OBDII code scanner (or manual) tells you something like "O2 sensor, Bank 1, Sensor 2":
View attachment 12208
What does upstream and downstream mean?
Simple, upstream means the O2 sensor is "upstream" of the catalytic convertors, meaning before the catalytic convertors. Downstream means the O2 sensor is "downstream" of the catalytic convertors, meaning after the catalytic convertors.
What brand of O2 sensors should I use for replacements?
Pay close attention to this one so you can do it once and do it right! The Jeep Wrangler TJ is extremely sensitive to all oxygen sensors other than NGK / NTK. Bosch O2 sensors and all the others (including the crappy Chinese brands you'll buy at your local auto part store) are very well documented as not working properly with our TJs. In other words, you plug them in and you assume all is well, until you notice your check engine light isn't going away. This is almost always due to the fact that you didn't use an NGK / NTK replacement O2 sensor.
Okay, so why don't other sensors (i.e. Bosch) work on our Jeeps?
Glad you asked! Check out this video for a detailed explanation of why other brands of O2 sensors don't work on our TJs:
So which O2 sensors do I need?
I'm going to break down which sensors you need based off what year your TJ is. The part numbers (and information) below were taken directly from the NGK website, so you can assure it is 100% accurate (even double checked each individual year and model before writing this thread).
4 Cylinder Engines1997-2000NGK #23506 - Bank 1, Sensor 1 (Upstream)NGK #23151 - Bank 1, Sensor 1 (Upstream) (1998 ONLY)NGK #23099 - Bank 1, Sensor 2 (Downstream)2001-2004NGK #23138 - Bank 1, Sensor 1 (Upstream)NGK #23141 - Bank 1, Sensor 2 (Downstream)2005-2006NGK #23159 - Bank 1, Sensor 1 (Upstream)NGK #23159 - Bank 1, Sensor 2 (Downstream)6 Cylinder Engines1997-1999NGK #23151 - Bank 1, Sensor 1 (Upstream)NGK #23099 - Bank 1, Sensor 2 (Downstream)2000NGK #23122 - Bank 1, Sensor 1 (Upstream)NGK #23506 - Bank 2, Sensor 1 (Upstream)NGK #23099 - Bank 1, Sensor 2 (Downstream)NGK #23099 - Bank 2, Sensor 2 (Downstream)2001-2003NGK #23139 - Bank 1, Sensor 1 (Upstream)NGK #23138 - Bank 2, Sensor 1 (Upstream)NGK #23142 - Bank 1, Sensor 2 (Downstream)NGK #23141 - Bank 2, Sensor 2 (Downstream)2004NGK #23137 - Bank 1, Sensor 1 (Upstream)NGK #23135 - Bank 2, Sensor 1 (Upstream)NGK #23132 - Bank 1, Sensor 2 (Downstream)NGK #23531 - Bank 2, Sensor 2 (Downstream)2005-2006NGK #23018 - Bank 1, Sensor 1 (Upstream)NGK #23160 - Bank 2, Sensor 1 (Upstream)NGK #23159 - Bank 1, Sensor 2 (Downstream)NGK #23158 - Bank 2, Sensor 2 (Downstream)Misc Installation Notes
When installing new O2 sensors, be certain to use some anti-seize on the threads of the new O2 sensors! This is important, and will save you a huge headache should you ever need to remove them in the future.
In addition, a O2 sensor socket will greatly aide in the installation and removal of O2 sensors. I recommend this one.
Not sure this was posted, I have an early 2000 TJ I purchased in December 1999, contrary to this chart, some early 2000 6-cylinders may only have 2 sensors, upstream/downstream of the catalytic converter.
Well I dont just want to replace them if I don't need to, I bought all 4 NTKs for my 06 from RockAuto almost 3 months ago after I got the CEL and codes for both upstream only to be told they are no good for my export model by a USA 4x4 specialist in Australia! now given the correct NTKs cost up to $800 in Australia I dont want to change them if I really dont need to. I got all 4 shipped from RockAuto to AU for $180 US including the removal socket.And it’s also best to replace the sensors in pairs (according to RockAuto/OEM). Plus they are kind of annoying to replace so you might as well kill 2 birds with one stone. I prefer using an O2 sensor socket as well.
All hail to the NTK O2 sensors. Fixed. Engine code for senors gone!Excellent thread. Just orders new "correct" sensors. Looking forward to posting my success.
Hahaha I would DEFINITELY hold off on that then! Damn that’s a bummer from down under...Well I dont just want to replace them if I don't need to, I bought all 4 NTKs for my 06 from RockAuto almost 3 months ago after I got the CEL and codes for both upstream only to be told they are no good for my export model by a USA 4x4 specialist in Australia! now given the correct NTKs cost up to $800 in Australia I dont want to change them if I really dont need to. I got all 4 shipped from RockAuto to AU for $180 US including the removal socket.
So my real question is if o2,s cost you as much as they will cost me would you guys still change them if the codes and CEL have not come back in almost 3 months?