O2 sensor bad= poor gas mileage

cre · 02-11-2012, 12:15 AM

Yes, the actual sensor is the same... Same part number even. The method of testing in the TSRM isn't 100%... You'd need an oscilloscope and Toyota's advanced diagnostic publication to really test it. Has the air bypass screw been tampered with?

Conga1991 · 02-11-2012, 05:00 AM

I couldn't tell you... the screw is 3/4 of the way in looking into the chamber. Not sure if that helps or not.

cre · 02-11-2012, 06:46 AM

If you can see the screw, then the pressed in cover had to be drilled out and it's most like been screwed with (hehe.... pun)... See my thread in the FAQ on how to reset it to it's factory position. This isn't going to be the source of your error codes but may further contribute to fueling issues (especially if it's in further than spec).

Conga1991 · 02-12-2012, 02:56 AM

I'm sorry, I was referring to looking inside the chamber of the afm. the pressed in cover is still their, hasn't been tampered with.

Also I fixed the problem, didn't even think to check the wiring at the connector, it was bear with lots of PS fluid on it, cleaned it and now no more code 34 or 42. Drove around my neighborhood with the diagnostic jumpered and have a code 51. Must be because of no A/C.

Cre, Thank You! Without you I would be a lost cause not knowing what to look for. I know UTI will help me with that =)

cre · 02-12-2012, 04:20 AM

Fix the code 51 if it's genuine. You cannot set the ignition timing with any error codes present. The code 51 won't stay stored. If you press the throttle while in diagnostic mode you'll get a code 51 but if you take your foot back off the throttle and the A/C signal is correct (off) then the code will go away again after 30 seconds or a minute.

No sweat.

02-11-2012, 12:15 AM	#1
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Yes, the actual sensor is the same... Same part number even. The method of testing in the TSRM isn't 100%... You'd need an oscilloscope and Toyota's advanced diagnostic publication to really test it. Has the air bypass screw been tampered with? __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

02-11-2012, 06:46 AM	#3
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	If you can see the screw, then the pressed in cover had to be drilled out and it's most like been screwed with (hehe.... pun)... See my thread in the FAQ on how to reset it to it's factory position. This isn't going to be the source of your error codes but may further contribute to fueling issues (especially if it's in further than spec). __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

02-12-2012, 04:20 AM	#5
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Fix the code 51 if it's genuine. You cannot set the ignition timing with any error codes present. The code 51 won't stay stored. If you press the throttle while in diagnostic mode you'll get a code 51 but if you take your foot back off the throttle and the A/C signal is correct (off) then the code will go away again after 30 seconds or a minute. No sweat. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

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02-11-2012, 05:00 AM	#2
Conga1991 3" Exhaust Join Date: Jun 2009 Location: Avondale, AZ Posts: 169	I couldn't tell you... the screw is 3/4 of the way in looking into the chamber. Not sure if that helps or not.

02-12-2012, 02:56 AM	#4
Conga1991 3" Exhaust Join Date: Jun 2009 Location: Avondale, AZ Posts: 169	I'm sorry, I was referring to looking inside the chamber of the afm. the pressed in cover is still their, hasn't been tampered with. Also I fixed the problem, didn't even think to check the wiring at the connector, it was bear with lots of PS fluid on it, cleaned it and now no more code 34 or 42. Drove around my neighborhood with the diagnostic jumpered and have a code 51. Must be because of no A/C. Cre, Thank You! Without you I would be a lost cause not knowing what to look for. I know UTI will help me with that =)