98 Explorer XLT 4.0 SOHC
108,555 mi

Code = P0133 (Bank 1 Sensor 1 - O2 Sensor CKT Slow Response)

AutoZone sold me an O2 sensor and told me it is the one before that cat. It is on the drivers side. I can access the sensor easily, but it plugs in between the firewall and behind the engine.

How on earth do I get in there to unplug it!!!???

 

Headshrink, the (Bank1 Sensor1) O2 sensor is on the passenger side, not the driver's side. It's also hard to access though. You will probably have to remove part of the exhaust pipe, or the plastic fenderwell liner to get to it. The fenderwell liner will probably be easier to take out.

Good luck,
TLR

 

I keep seeing reference to the passenger side, but I swear it is on the driver side. I wonder if we are talking about different sensors?

I did finally get it out. I unscrewed it from the pipe, pulled it up to the top, was able to get my hand in enough (ouch) that I could pinch the clip. Then I pulled on the wire and it disconnected. I also disconnected the neg on the battery for several seconds in hopes of reseting the code. The Check Engine light stays off now

If only my tranny worked and engine didn't overheat.....

 

You probably have 3 O2 sensors like my 97. One in each side of the Y-pipe and one back by the cat. Bank 1 Sensor 1 is passenger side, same side as cylinder 1.
For bank 1 I remove the flexible liner and go in thru the wheelwell. For bank 2 sensor 1 I lay under the truck and get it from there. Bank 2 sensor 1 plug is up on top of the tranny and is harder for me to get than the plug for bank 1.

 

Headshrink, if the code is truly P0133, then it indeed refers to the passenger side O2 sensor. Hate to say this, but I'll just bet the code will return......

 

So which sensor does it sound like I got?

 

The bank 1 is the passenger side, and sensor 1 is the one closest to the exhaust manifold. I suspect the MIL went off because you disconnected the battery. Since you've already changed the driver's side, keep the old O2 sensor, and if the light comes back on put that one in the passenger side. They're the same except for the possible exception of the wiring length.

If the MIL is off for now, you're OK. What I'm saying is that it might come on again, perhaps after some highway driving.......

 

Good thing I don't do much highway driving

So I can put the used one I yanked in the other side if the code returns?

 

And you were apparently right. The light is back on now.
Last night I flushed the radiator and replaced the thermostat to fix an overheating problem and replaced the nasty air filter. The overheating seems to have ceased, but perhaps when I was test driving it hard it encouraged the CE light to come on a bit sooner than expected.

 

Sorry the MIL's back on, Headshrink. 'Spirited' driving, or sustained interstate driving will reset an O2 code if it's borderline. If the O2 wiring harness on the old one is long enough, just install in on the passenger side. If not, you'll need to get another new one. One thing to consider is the amount of work to install it. If it's hard to get to, it might be wise to put another new one in anyway, just to prevent having to change it again soon......

 

Where can I find info on accessing it? Or is it really easy to describe?
I just got a manual from Hayes, but there are a lot of steps that seem to be missing, like how to get to things. They assume you already have some knowledge.
BTW: I am pretty new at doing my own repair work.

 

Ahh, I see you did describe it.... I will crawl down there and try to figure it out.
I read another post about removing the console and cutting carpet, same sensor?

 

I've heard rumors of a removable panel being down there, but haven't checked on mine. It might be easier to just remove the plastic inner fenderwell panel. It's held on with plastic clips that can be pried off. Fairly easy after removing the wheel. Good luck.

 

The console removal is probably only necessary on a 5.0L. You don't necessarily have to cut the carpet, it can be rolled back, on the 5.0L

 

Yeah loneranger - I've had to pull back the carpet on my 93 Explorer to change the M5OD shift rail plugs. But where the cover is located, it opens up more towards the rear of the car and not where the O2's are - at least on my truck.