Yeah, and I'm going to guess that it won't make a difference, but right now you have at least some evidence that it could be the problem.

You could go about this a little more scientifically by getting a scan tool that will measure voltage, or if you want to get real flashy, an inexpensive PC-based oscilloscope to see what the sensors are actually putting out:




I've been running O2 CELs nearly continuously for 5 years for a number of reasons (broken wire, dead sensor, new post-cat sensor measuring > pre-cat sensor etc.) but never had a problem with performance. Being frugal (cheap) I'll often just let it go. If the sensors are putting out something even CLOSE to normal, you shouldn't see a difference.

As an aside, the 2000 post-cat sensors DO participate in the algorithm.

But again, since you have performance issues with the code, IMO you're kinda beholden to change it out, but see if you can get a voltage measurement before you do.

BTW is the new CPS a Mopar?

 

Broken O2 sensor wire:

 

For other purposes... Some valuable information to know is that the oxygen sensors circuitry is linked up with many other circuits. A shorted oxygen sensor wire has the ability to interfere with the correct functionality of the Crank Position Sensor (CkPS), to cause very poor running conditions to occur in this way as well.

 

I will be replacing both upstream friday or Saturday I'll keep you guys posted. An should I worry about the p0325 knock sensors. I was gonna replace that to but can't find the part number . I think it's located driver side back of the engine

 

That sounds reasonable. I am sure both of the upstream oxygen sensors are of an older age right now as it is. If the problem persists in the one bank like it is now after replacing both of them? The next likely thing is a shorted wire may be the cause of this issue at that point. Then, you can find and fix the wiring. In the end, you will have fixed the problem either way. And you will have a better operating system with the two new oxygen sensors being put in there at that point as well.

 

You should definitely be concerned about the Knock Sensor code just so you know.

This code means there is pre-ignition happening inside of the combustion chambers. The Knock Sensor is detecting an abnormal shock wave that is occuring in addition to the shock wave produced by the spark plugs. The abnormal shockwave is happening ahead of the flame front from the spark plugs. This will greatly increase the pressure in the cylinders. It can cause catastrophic damage to the engine, including cavitation or even perforation of the piston crowns!

The PCM has been recieving the signal from the Knock Sensor, and it has been trying to adjust timing to correct the knock. The PCM has not been able to do it, and it has thrown the code for you to see it (it takes a little awhile to set this code).

This is possible it may be the result of having a bad oxygen sensor? I do not know though? This could very well mean the problem your Jeep is having runs deeper than that?

This would make me want the data prior to replacing the oxygen sensors a little more than ussual. If it were me, I would want to be able and compare the before and after data if I was planning to replace the oxygen sensors. I would not want to not know.

 

P0325 and P0132 are both codes being thrown from the same engine bank. These two codes correlate with each other. It sounds like definitely a for sure problem on your bank 1. There should be a sense of haste in getting this problem repaired so there is no damage (or further damage) to the engine.

The main reason for the P0325 code is due to having an excessively lean engine running condition. This correlates very well with having a bank 1 sensor 1 oxygen sensor code high voltage. The oxygen sensor is telling the PCM that the bank 1 is running excessively rich, when it probably is not, and the PCM could be drastically limiting the fuel supply and causing an excessively lean running condition to occur on this bank right now.

The other main reason for having a Knock Sensor code is because of having a problem with the engine coolant temperature readings. If this were the reason it would be more of a global problem happening on both banks 1 & 2. It would still be good to check the engine temperature comparing it to the gauge if possible.

 

I am experiencing same symptoms as you but with a code for crankshaft position sensor. Took it to a local garage as I could not figure good way to replace CKS. They replaced but have same problem. Since it only occurs when engine warm, meaning cat converter is warm we are now in closed loop and O2 sensor is passing data to computer. I am going to hook up my scan tool and see what voltages I am getting from O2 sensors. If flat lined once in closed loop will replace O2 sensor. Also going to check voltages on camshaft position sensor. Should be 5 volts from computer. Will backprobe sensor to check for 5 volts once circuit closed.

My STFT is oscillating around 40% while LTFT is almost flatlined at 0%. This leads me to think camshaft sensor is bad

 

I think you guys have opposite type of similar problems. It is kind of interesting that for him we know the oxygen sensor voltage. And for you we know the fuel trim values (some of the fuel trim values anyway). And at the same time, we know nothing about either of both banks for neither of your cases. We know for him the oxygen sensor voltage is high on just the one bank (via a code). We do not know the other bank though. And for you we know fuel trim percentage is high on one bank. We do not know the fuel trim values on the other bank though. We do not have either of the other banks in questions values. And we only have half of the picture for both cases concerning the oxygen sensor voltages and the fuel trim values.

I am assuming by you saying 40% fuel trim (STFT) you mean this as a (+) fuel trim value, and not a (-) fuel trim. It could be 40% (+) or 40%(-) trim... If your one bank is indeed showing as being 40% in the 'positive'. This means the computer is adding in A TON of fuel via the injector pulse width being lengthened. This would mean your oxygen sensor for this bank is telling the computer that your engine is running extremely lean, when it probably is not. This would be an oxygen sensor having a 'low' voltage as showing inversely related to the oxygen content being detecting in the exhaust gasses (probably most likely falsely detected at that). The fuel system lambda proxy mess is not an intelligent system. It does not know any better than to do what it is told to do by the sensors. Because of this, I believe you have a short to ground somewhere on whatever bank this is? On this banks oxygen sensor wiring. A short to ground on this part of the circuit would send a voltage value of '0' to the computer. The computer would think the 'low', '0' voltage, means there is a whole lot of too much oxygen in the exhaust gasses. Which means to the computers interpretation that the engine is running very lean and is telling the computer it needs to inject a whole lot of extra fuel into the system in an attempt to gain back the normal 14:1 stoichiometric air:fuel ratio as how it should normally be doing. This, plus a short on an oxygen sensor wire can and has been known to adversely effect the Crank Position Sensor (CkPS), and at one point you had a code for this...

I wanted to try and help you a little. And I believe both of you guys could learn from each others problems. However, as you can see the things we are talking about are confusing enough on there own. Mixing both of your Jeeps problems together in one single thread may lead to possibly even further confusion. Especially, since it sounds like you and him have different similar-type.. but probably opposite issues of the same. I would think everything may go smoother and better for both of you guys if you were to start your own specific thread on what is happening on your Jeep exactly how it is happening specifically for your Jeep. Maybe watch each others threads and learn from each other, and help one another if you are able to. Just as a suggestion.

I would get both STFT and LTFT values for both banks. I would also want to know both banks upstream oxygen sensors voltages. Make sure you get the fuel trims after the Jeep is fully warmed up and is in a closed loop operation.. on three readings for one minute each, to compare the values while at idle, 1500 RPMs, and at 2500 RPMs. The fuel trim values will change depending on what is happening additively vs multiplicatively for the different types of specific problems that may occur. For example, having a vacuum or exhaust problem vs having a fueling or sensor problem respectively.

 

Agree to move to separate thread.

 

So I'm about to start the project in a little bit but it looks like there's only one upstream O2 in 1 downstream but I do see a loose plug that looks like it goes to an O2 sensor the one upstream is connected maybe the previous owner swap exhaust from the older Cherokee so is there anyway to bypass the one that is disconnected or do I have to install another O2 sensor

 

I think you're either going to have to explain that a little better or post an image of what you have.

If you originally had a CA exhaust there should be two unplugged... plugs.

 

I'm digging into it later but it looks like I have 1 02 right before the cat at 1 right after underneath not near the header and then when I looked it looks like another 02 connector was disconnected up top near the air box

 

 

I do not know the reasoning behind why the California model Jeeps have the extra oxygen sensors as compared to the non-Califonia models? I am not sure what the the effect of those extra oxygen sensors are? Except to know somehow and in some way the Engineers added the extra oxygen sensors for environmental reasons.

Maybe someone else knows why? Or, what the effects would be if someone were to remove and disconnect them from the Jeep like that? The only thing I can think of right now is the previous owner removed them (or at least that one from the picture there.. which probably should be connected up to another oxygen sensor I would think?).. maybe the previous owner removed them because of having an issue occuring that was causing the Jeep to have some sort of bad running conditions? Maybe this was a half-baked attempt by whoever had the Jeep back then to sort of kind of try and fix whatever may have been the issue?

I do not really know though? What are the reasons for extra oxygen sensors on California model Jeeps? How do the extra oxygen sensors effect the performance of the overall system? And what happens when they are removed?

(edited):
Could it be that it is just a connector in-place to be used only if converting the Jeep to a California model to meet the requirements of the State? Maybe someone was wanting to take the Jeep to California with them for whatever reason, and they were in the process of trying to get it set up to pass a California inspection?