Sherpa

I have been checking out the URD website and find there are two oxygen sensors. How do I figure out which O2 sensor is bad on my truck so I know which one to replace?

I searched the forum yesterday and found a lot of threads on O2 sensors, but didn't find anything to answer my above question.

Thanks.

Sherpa

Bob_98SR5

an OBDII code reader will tell you

bob

ASU4runner

Scan it with an OBD-II code reader (Free at most autozones) and find out what sensor it is. I know bank 1 sensor 1 is the sensor just before the catalytic converter. I had to change this one on mine. Good luck.

Sherpa

Thanks to both of you. I'll try to find an AutoZone this weekend.

-Sherpa

MTL_4runner

This is the most common of the 2 O2 sensors to go out since it is upstream of the converter.
Need to scan with an OBD II tool to know for sure.

BOSTON4RUNNER

commonly,,,,P0135 code comes up for the sensor in front of the car

and P0136 comes up for the sensor behind the cat

BOSTON4RUNNER

you def will need an OBD2 scanner, they sell them for like 40 bucks now I think,,,,,

Sherpa

I haven't found an OBD II scanner for a reasonable price, yet, but I'll keep looking.

I did go to AutoZone the other day and found the code: P0171 "Bank 1 too lean".

I took my MAF housing out of the intake system and "cleaned" it again. Since I couldn't find a way to disassemble it any further than I the large plastic piece, I simply took electrical cleaner and sprayed enough into the piece to create a puddle. I then agitated the cleaner to wash the MAF wire. I repeated the process a second time with a little more cleaner fluid and then reinstalled the piece.

The truck started right up. I buttoned up the truck and went inside for a while. Later I decided to head over to Advance Auto Parts (much closer than AutoZone) and pick up some other parts. I started Sherpa but couldn't keep him running. It took 4 tries for the truck to start and keep itself from immediately stalling. Once started, I found that the truck really didn't want to run well, but I had to get to Advance. I decided to head out. I pulled onto the street and let it slowly run up to about 3,500rpm. As soon as I hit 3,500rpm the thing lost all power and just about stopped. I repeated that another time or two before deciding the thing wasn't safe to drive anywhere. I turned around and went home... pissed.

I popped the hood and took another look inside to see if I could resolve my other problem without going to Advance. I glanced over at the MAF and found that I had forgotten to reconnect the electrical connection!!!
I plugged the darn thing in, pulled the fuse again to reclear the computer and fired Sherpa up again. At first the idle was rough, but soon smoothed out and it is now running better that it has in quite a while!

Now I need to get back in touch with Gadget and order that fuel upgrade kit!

-Scott

MTL_4runner

P0171 is almost always MAF so glad it sounds like you got it back running right again.

Sherpa

Me too! The funny thing is I didn't have these problems when I heavily oiled my Amsoil air filter. Now that I have cut back on the amount of oil I am using on the foam, I have/had this problem. Strange.... I think I'll go back to putting more oil on it, like it had from the factory.

-Sherpa