2000 Toyota 4Runner Limited, 3.4V6 with California Emissions (two cats instead of one, different O2 sensor part numbers, and computer flash).

Threw a CEL Friday. Autozone pulled two codes:
P1130
Air/Fuel Sensor Circuit Range/Performance. (Bank 1 Sensor 1)
P1133
Air/Fuel Sensor Circuit Response. (Bank 1 Sensor 1)

Advice?

History: Back in December I got a P420 code (catalytic converter), but I had been chugging around Raleigh in the snow at low speed for a couple of hours. I cleared it and everything has been fine since. Other than that I can't think of anything relevant.

[Edited on May 15, 2011 at 12:44 PM. Reason : l]

5/15/2011 12:39:54 PM

http://www.ncttora.com/fsm/1996/SIL/techinfo.toyota.com/ileaf/02toyrm/02toypdf/02rmsour/2002/024runne/di/eg5vzfe/parloc.pdf

So, based on this it looks like Bank 1 sensor 1 is my front O2 sensor? I'm going to start by cleaning the MAF, checking the front 02 sensor wires for damage, and clearing the code. If it comes back I'll order a front 02 sensor unless the TWW gurus advise otherwise.

[Edited on May 15, 2011 at 6:10 PM. Reason : l]

5/15/2011 6:08:40 PM

Quote :

"I'm going to start by cleaning the MAF"

in my experience this makes a world of difference

5/15/2011 6:39:00 PM

bank one upstream sensor is probably switching too slow, if its original it wouldnt be a big surprise if it was time to replace it. usually best to go ahead and replace both upstream sensors so as not to make the other one look slow.

5/16/2011 12:07:55 PM

When you say both upstream sensors are you referring to the two O2 sensors?

5/16/2011 12:21:56 PM

yes

5/16/2011 1:34:03 PM