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Discussion Starter · #1 ·
I finally got all of the exhaust leaks fixed, and my sputtering and backfiring seems to be gone. The only leaks I had was between the cat and muffler, but there were a lot of them! I'm showing a code 21 and a code 54 now. I know that I need an O2 sensor, so I'm not worried about the 21, but the 54 is cam sensor. Am I correct that the cam sensor is inside the distributor? Also, does it require removing the distributor to change? I did a search here, and also a google search, but am not seeing anything definitive.
Thanks again for all the good advice!
Darren
 

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change the whole dist .Advanced auto has them with a lifetime warrenty .real easy to change.the bushing go bad .I forget how much.I think its like 40 bucks.
 

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Discussion Starter · #3 ·
I looked it up and the entire distributor is only $11 more than just the sensor.... I guess that's a no-brainer. Thanks for the info!!
 

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Discussion Starter · #4 ·
Ok, new distributor installed, and now I'm back to the original problem. Driving down the road and this thing randomly starts bogging, as if it is running out of fuel. If I stay on the throttle, it finally starts popping through the intake a few times, and then a backfire through the exhaust. (a really loud backfire- sounds like a shotgun.) I'm assuming that this means that rather than running out of fuel when it starts to bog, it is actually flooding. I am getting a code 21 and code 52, which are both O2 sensor problems. I haven't been able to locate a new sensor yet, but I have never had any other vehicle do this from a bad O2 sensor. Would it help to just disconnect the sensor until I get another one? This is the original problem that I had when I was driving the jeep home last weekend when I originally purchased it. I have been thinking that it was water in the fuel, and have run a couple of bottles of heet through it. It did seem to get a little better. Then I fixed all exhaust leaks, and it worked fine for the 5 mile drive home. Now here is the wild card... I put an aftermarket cold air kit on it this morning because someone had mangled the factory air box. I did connect the vacuum line that goes to the unit under the brake booster, and I also connected the crankcase vent line that goes from the valve cover to the intake. I'm a little lost here... should I be looking for another factory airbox? Help!!

Also, it's a '95 with the 2.5L 4-cylinder. Have also installed new plugs, wires, distributor cap, and rotor button. I did just eyeball the plug gap, and am wondering if that may have added to my troubles.
 

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Discussion Starter · #6 ·
I've got this same problem and I see it hasn't been answered in years...by chance did you figure it out?
I finally changed the oxygen sensor, and haven't had a problem with it since. I never thought an o2 sensor could cause a vehicle to run that bad, but on this jeep, it really did.
Good luck!
Darren
 

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Yep, the 02 sensor is what controls the stoichiometry of the entire mixture. Basically the 02 sensor tells the computer to add more or less fuel to achieve as perfect of a blend of gasoline and air as possible for best fuel economy and power. If the 02 sensor isn't working right, it might constantly tell the computer there's too much fuel in the system, or it might say the computer needs to really richen it up.
 

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That's crazy, i've had bad O2 sensors before and they never did that either...thank goodness you still get on here Lol...you named my symptoms to a T
 

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Yep, the 02 sensor is what controls the stoichiometry of the entire mixture. ....
Wrong, again...

the O2 sensor is the fine tuner, the computer actually looks at the o2 sensor LAST when performing Air/Fuel ratio adjustments.

MAP (Manifold Air Pressure) sensor (Basically a engine vacuum sensor)
Coolant temp sensor

those are your primary sensors, combined with RPM, the computer assigns a base mixture.

If your Coolant temp sensor is intermittnetly sending a -40* signal, your going to bog down due to too much fuel.

If your MAP sensor is disconnected from vacuum, your computer thinks your at full throttle all the time, and dumps fuel

If those sensors are telling the computer bad information, the computer sees RICH at the o2, and sets a code for o2.

Our computers are dumb, they run on a set of parameters that are pre-set according to 1995 technology, and are prone to logic flaws that seem obvious to us.

OK, here is the kicker, and this tells me the O2 is not the issue, if the computer sets an O2 code, it starts ignoring the O2 sensor, basing its Air/Fuel output on a pre-defined chart, since your Jeep is STILL having issues (before you replaced your O2 sensor), its still getting bad data from SOMEWHERE. Start checking voltage and resistance in your sensors, Id start with your Coolant temp sensor, then MAP sensor.

Regardless, running so rich can easily mess up an O2 and Cat Converter, so definatly find your issue BEFORE replacing those, and yes, at this point I would disconnect your O2 sensor.

Since you already replaced your O2, PLEASE check your other sensors, I would HATE to see you have this same issue in 4-6 months...
Chances are, when you replaced your O2, you mussed tyhe harness and/or disconnected your battery? reset the computer losing the code.
 

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You know what I mean. A failed 02 sensor is more than enough to miserably fail emissions, so that says something of its importance. not to mention a vehicle can run worse than it should be.
 
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