minidisc8

I recently had the codes read on my 95 Runner and got a 25 Too Lean AND and 26 Too Rich. The guy says that one or both of my O2 sensors is probably bad because he was not getting and actual amperage reading from them. He wants about $150 to figure out what sensors are bad then who knows what to replace them. I figure I can replace them myself for much less. Does anyone have any idea which sensor would be bad based on those codes? Or should I just replace both? I have read that there are two on my truck, where are the located?
Thanks in advance.

mtnfreak

Made any mods or done any work on the engine/exhaust lately? If so, wait a few hundred miles before you give somebody your hard earned $. The problem may clear up by itself after things adjust. That's what happened after I got the same codes right after changing my O2 sensor. I guess the computer finally agreed with me that too rich + too lean = just right.

heliax

I thought 95s had only one O2 sensor? That or I'm not up on my 4runners hehe. It is a sensor in your exhaust a little downstream of the block. Take a peek under there and check it out. It will have some wires coming out of it. If there is one, it will be in front of the cat, if there is two, there will be one in front of and one after the front cat.

minidisc8

mtnfreak-no mods to exhaust or anything.
I hae 126,000 miles and i think the sensor(s) bad.
As for confirming 1 or 2. Does anyone else no. I might crawl under there soon and see for myself.

AgRunner06

I'm pretty sure that it is only the CA emissions vehicles that have 2 O2 sensors. Otherwise you should have one sensor in front of the cat. I would just replace it and pull the EFI fuse to reset the code.

Before you replace it, could you try something for me? I was told by a service man at Toyota that you can pull out the O2 sensor (when cold) and spray it with carb cleaner. Then just let it dry and put it back it. Supposedly it might fix the problem. I'm interested to see if this works. Plus it might save you $140.

Good Luck

mtnfreak

In '95, I think only the vehicles with California Emissions had 2 sensors. Everyone else had only one. Either way, they're not hard to spot - looks like a big bolt sticking out of the exhaust pipe with a wire coming off the other end. Might have a small half-shield in front of it.

Dang, college-boy was faster.