friedk

I will get under there again and look. To me it seemed that the nut was welded on as part of the bung on the pipe. I could not see where the sensor would screw in/out. Ill let you know if I find anything odd. I assume they are the standard 7/8 or 22mm?

Or does the sensor just thread out from the nut on the exhaust. If so will the nut spin?

I see the nut welded onto the exhaust pipe however I dont see a nut on the O2 Sensor. Should it look like there are two nuts... one welded to the pipe and one on the sensor?

Looking for some suggestions. I am trying to get my O2 Sensor out of my 95 Pathfinder. When I get up in there and remove all of the rust around it I cannot seem to find where it threads in. It almost looks like the whole unit it welded in. any suggestions?

I will keep that under my hat for consideration... Thanks How do I determine if my problems is the O2 sensor vs a bad catalytic converter. Could the catalytic converter create back pressure only when the engine is warm and under a load... or if the catalytic converter was bad wouldnt it give me problems constantly? I hate to replace one and find out it is the other. Sorry guys I am not much of a mechanic but always learning so thanks for your help.

I took it for a short trip today and got the engine up to running temp. No error code, things seemed to run just fine as usual when not loaded on a trip. I unplugged to O2 sensor and nothing seemed to change at all. I do notice an odd smell at the exhaust, not like rotten eggs but a strong odor. During my test the check engine light did not come on. Seems that this is related to the O2 sensor or wire which seems in tact. Any thoughts about a plugged cat?

If I took the shield off do I need to put in a spacer?

Ok, I just dont want to miss something else that could be the problem. Because it occurs only when the truck is loaded and the engine heats up on secondary roads. I suppose that the O2 sensor could be weak and heating it up is enough to cause it to malfunction. I am finding exact fit O2 sensors from $85 (Autozone) to $105 (NAPA)

My front disc brake dust shields are rusted almost off. I have had to peel them back from the rotor a couple of times to keep them from scraping. Does anyone run their's without the dust covers? I am considering just taking the covers off and leaving them off. Thanks

Might I be able to replicate the problem by running the engine and wiggling the wire from the top to see if this affects the idle? If it was a wire why do you think the problem would only occur when the truck is loaded with gear and on secondary roads? Before reading the code I thought it might be more of a heat issue. But the engine does not seem to be overheating.

Can anyone assist me I have a 5Spd 95 Pathfinder that I use for camping trips in the summer. I noticed that last year when loaded down with my 2 kayaks on top that the check engine light comes on pretty quickly especially on secondary roads. Soon the engine will sporadically begin to lag, almost stutter while my foot is on the accelerator. It will come out of this rough period only when I really give it quite a bit of gas. When nothing is in the truck and I am taking it to do my errands none of this happens. Distance, Weather etc does not seem to matter. The only thing that I seem to note is that it will not do it as easily on the highway. So it seems to occur more on secondary roads. The engine does not apear to be overhead but this occurs when the engine is at running temperature usually traveling at lower speeds. During these periods that the check engine light is on it does not run rough constantly. After I unload everything the error code clears and it seems to run normally. The computer gives me error code 33 - the o2 Sensor I am not sure if I can self test the 02 Sensor by pulling it out and see if it runs better because it only runs rough as explained above. Should I just replace the sensor and see how it does on my next trip? The one thing that seemed to start this is I had an exhaust leak at the top of the Y pipe on the Pass Side last year that on one trip it really heated up the fire wall and that was the first time the check engine light came on. I have since replaced that section of the Y hopeing it would cure the problem. But it has only fixed part of the problem. Thanks for your imput.