[ExtremeGuy]

I own a 1997 SR5 V6. Receintly my CHECK ENGINE light came on and from the recomendation from this forum, I bought a code reader (really cool gadget!!!)

Well, the code reader told me that the o2 sensor (after the cat.) was bad. I called the 3 different dealers and they all told me about the same thing about the cost to replace this, about $150 for the part and at least 1 hour of labor.

I wanted to do this myself, so I checked out my Chilton's manual and found the location of the sensor, which is out in the open. The only problem is that the part is really rusted on and the nuts holding it on are gone (rusted away). I am afraid that if I try to take this off, I will end up creating a bigger problem, so ultimately I will end up taking it in to have a dealer fix this.

QUESTION: Now, the question I have is: How important is this o2 sensor? Will my truck be fine without it for a while or is it criticle to get it replaced? Also, is the price that I was quoted sound reasonable? I mean, the part looks small and basic.

Thanks!

[TSP-MIKE]

$150 for an O2 sensor is right. An hour labor is questionable. It only takes 5 mins to change out the O2 sensor.

The O2 sensor is important. The second O2 behind the cat reads the exhaust gas after it's been converted. If it reads that the car is running too rich or too lean, it will compensate for it by adding or subtracting fuel. if it takes out too much fuel your car will actually run lean but the bad O2 sensor will tell the computer it's running normal.

Mike

[ExtremeGuy]

Thanks! You told me what I didn't want to hear (that I really need to replace this sensor). The hour of labor is mostly b/c of the amount of rust on the sensor and that they need more time to take it off and rethread screws to put the new one on.

[.o2 Lost Hiker]

Most (if not All) dealers will give you an hour labor estimate. All dealers I've gone through always charged me an hour minimum. The only time they don't charge you an hour is when you get an oil change.

[bigmike21]

after research on here and on youtube i decided to tackle the O2 sensor job on my own for my 97 4runner SR5 V6...the Check engine light appeared and immediately went to go check it out CODE CAME UP P0136 Which indicated the rear (downstream) o2 sensor ..went on ebay found the correct part Bosch 13566 on the box, after talking to a Rep he confirmed the correct part for my truck i always like to double check!....got the part took out my ratchet set and begun ..prior to the part arriving i sprayed wd40 to loosen up the nuts not sure think they were 12mm ,,,,first i marked the plastic coupler part with a sharpie on both parts... one coming out and one the staying ,just to make easier when re installing..compared it to the new part and marked the correct side on that one with sharpie ....so then unhooked the plastic coupler by pressing tab on the back part and by inserting flat head screwdriver in between to loosen the connection...take your time it will pop off....then then took out the 2 mounting nuts on the flange of the o2 sensor... thats all that holds it in...the sensor itself does not screw in like on alot of vehicles ,,,then cleaned around with wire brush to take off excess rust....put the diamond shape washer provided on the new sensor re installed it with new nuts and washers that i had in my nuts/screws box....reconnected the plastic clip make sure its in securely......now to reset the the code i simply disconnected the neg terminal to the battery for like 5 minutes..put it back turned on the truck and presto check engine like gone! took me like half hour and under 50$ ..satisfaction on doing it yourself is priceless! mechanics or AKA Rip off artists wanted between 75$-150$ for labor...and what ever the part costs them they charge you double as well...ha lol ....So read some threads do a little research ..slide yourself under your truck and save yourself some $$$$...hope this helps you guys take care

[DosPatos]

Nice workup to a (n) O2 prob. I have a 1999 4runner limited and the check engine light just appeared as well. So first things first , took my can of MAF cleaner and cleaned the MAF. No help. drove for a day no change. I think im picking up a code reader today and start from there. I did have a question, after all your work you still needed to clear by removing neg cable. wouldn't just starting and driving it should of cleared right?

[HammerHead]

Don't be surprised if the Bosch throws a code again. This has happened to a lot of us who we're trying to save a few bucks. Second time around get a Denso part. There are a ton of them online for a lot less than the dealer wants.

Now if you get lucky and it doesn't throw another code then count yourself lucky.

This is a good place. https://urdusa.com/