Car only starts when primary 02 is unplugged - Page 2 - Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community

j0hnnybk01 · 01-20-2016, 10:43 AM

Okay so i got a new 02 and still got the same thing going on . next is a maf going to return the 02 . I am really hoping its the MAF

j0hnnybk01 · 01-20-2016, 02:10 PM

okay so i started the car by unplugging the 02 sensor then plugged it back in . let it run until it just shut off . my codes are now
p0102 Mass or Volume Air Flow Circuit Low Input
p0462 Fuel Level Sensor "A" Circuit Low
p0113 Intake Air Temperature Circuit Low Input
p0031 Oxygen Sensor Heater Control Circuit High (Bank 1 Sensor 2)

j0hnnybk01 · 01-20-2016, 03:39 PM

Borrowed maf from another frs and still have the same issue.

steve99 · 01-20-2016, 10:48 PM

Quote:

Originally Posted by j0hnnybk01

okay so i started the car by unplugging the 02 sensor then plugged it back in . let it run until it just shut off . my codes are now
p0102 Mass or Volume Air Flow Circuit Low Input
p0462 Fuel Level Sensor "A" Circuit Low
p0113 Intake Air Temperature Circuit Low Input
p0031 Oxygen Sensor Heater Control Circuit High (Bank 1 Sensor 2)

Quote:

Originally Posted by j0hnnybk01

Borrowed maf from another frs and still have the same issue.

were those new codes or ones that may have been stored in ecu.
remove battery and press brake pedal to reset ecu

then check for codes again they might have been old ones

The intake air temp sensor is in maf sensor i believe.
fuel circuit is weird.

check maf connections.
check battery/alternator volts
check earth connection
check any other wiring you altered or moved

check for air leaks, especially catch cans and pcv valves blow off valves ..

j0hnnybk01 · 01-21-2016, 12:01 AM

those are the new codes . maf connections are good . grounds have not been removed . changed my pcv valve back to stock because i put a sti one on and still the same . I'm thinking its the throttle body . i poked it to see if i needed to clean it and now i think it is off. it says 0% when its not closed all the way and 95% wot . whines/ buzzes really loud when the key is on the ON position . i have tried to reset it by unplugging the battery for 30 min and plug it back in but still the same . i will be trying a throttle body next . $100 on ebay for a used one . that is the only thing i can think of . the car is putting out a lot of fuel when i try to start it and my oil is starting to smell like fuel because of it .

j0hnnybk01 · 01-21-2016, 03:05 PM

well i tried my best but can not figure it out . so its at my brothers shop maybe they can figure it out

Spartarus · 01-21-2016, 03:45 PM

"The bank 1 sensor 2 circuit" is the rear o2 sensor control circuit. It runs in parallel to the front heater circuit, off the same relay.. Damage to 1 will affect the other. You may have been searching the wrong sensor for wiring damage.

The IAT is in the MAF, so the 2 MAF-associated codes indicate a MAF problem as well.

The fuel code is strange, until you realize that the VSV runs in paralell to the rear o2 sensor as well. Damage to the wiring will/can affect the vacuum switching valve. (EVAP purge) which will screw with the fuel sensor.

The positive wire for that circuit also supplies the MAF, the throttle body motor, oil and coolant temp, fuel pressure, knock 1 and 2, with positive current.. If you unplug the rear o2, your problems may vanish.

Or, if the bad wiring has caused damage, you will have a lot of things to replace.

But, a short in the rear o2 heater circuit would explain all of your problems, all of your codes, and the strange noise from the throttle body.

It's the red and yellow wire in the rear o2 bundle. It becomes black and yellow at the engine, and then coterminates with a yellow and black wire that supplies current to all of the other sensors and systems I mentioned.

j0hnnybk01 · 01-21-2016, 09:36 PM

I have to say you are one hell of a guy helping me diagnose this problem ! i never had this much help on a forum before . i will try that when i go up to the shop tomorrow morning . hoping it wont be a fried ecu or need a new harness .

Kris86 · 08-28-2017, 12:13 PM

Quote:

Originally Posted by j0hnnybk01

I have to say you are one hell of a guy helping me diagnose this problem ! i never had this much help on a forum before . i will try that when i go up to the shop tomorrow morning . hoping it wont be a fried ecu or need a new harness .

did you ever get this issue sorted?

01-21-2016, 03:45 PM	#21
Spartarus ...Just add nauseum Join Date: Jan 2015 Drives: 2003 (AP1) S2000 Location: Miami, FL Posts: 546 Thanks: 310 Thanked 785 Times in 335 Posts Mentioned: 19 Post(s) Tagged: 1 Thread(s)	"The bank 1 sensor 2 circuit" is the rear o2 sensor control circuit. It runs in parallel to the front heater circuit, off the same relay.. Damage to 1 will affect the other. You may have been searching the wrong sensor for wiring damage. The IAT is in the MAF, so the 2 MAF-associated codes indicate a MAF problem as well. The fuel code is strange, until you realize that the VSV runs in paralell to the rear o2 sensor as well. Damage to the wiring will/can affect the vacuum switching valve. (EVAP purge) which will screw with the fuel sensor. The positive wire for that circuit also supplies the MAF, the throttle body motor, oil and coolant temp, fuel pressure, knock 1 and 2, with positive current.. If you unplug the rear o2, your problems may vanish. Or, if the bad wiring has caused damage, you will have a lot of things to replace. But, a short in the rear o2 heater circuit would explain all of your problems, all of your codes, and the strange noise from the throttle body. It's the red and yellow wire in the rear o2 bundle. It becomes black and yellow at the engine, and then coterminates with a yellow and black wire that supplies current to all of the other sensors and systems I mentioned. __________________ There are many ways to displace. -Spartarus Last edited by Spartarus; 01-21-2016 at 03:56 PM.

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01-20-2016, 10:43 AM	#15
j0hnnybk01 Member Join Date: Oct 2013 Drives: Firestorm FR-S Location: Charlotte Posts: 51 Thanks: 4 Thanked 5 Times in 5 Posts Mentioned: 0 Post(s) Tagged: 0 Thread(s)	Okay so i got a new 02 and still got the same thing going on . next is a maf going to return the 02 . I am really hoping its the MAF

01-20-2016, 02:10 PM	#16
j0hnnybk01 Member Join Date: Oct 2013 Drives: Firestorm FR-S Location: Charlotte Posts: 51 Thanks: 4 Thanked 5 Times in 5 Posts Mentioned: 0 Post(s) Tagged: 0 Thread(s)	okay so i started the car by unplugging the 02 sensor then plugged it back in . let it run until it just shut off . my codes are now p0102 Mass or Volume Air Flow Circuit Low Input p0462 Fuel Level Sensor "A" Circuit Low p0113 Intake Air Temperature Circuit Low Input p0031 Oxygen Sensor Heater Control Circuit High (Bank 1 Sensor 2)

01-20-2016, 03:39 PM	#17
j0hnnybk01 Member Join Date: Oct 2013 Drives: Firestorm FR-S Location: Charlotte Posts: 51 Thanks: 4 Thanked 5 Times in 5 Posts Mentioned: 0 Post(s) Tagged: 0 Thread(s)	Borrowed maf from another frs and still have the same issue.

01-21-2016, 12:01 AM	#19
j0hnnybk01 Member Join Date: Oct 2013 Drives: Firestorm FR-S Location: Charlotte Posts: 51 Thanks: 4 Thanked 5 Times in 5 Posts Mentioned: 0 Post(s) Tagged: 0 Thread(s)	those are the new codes . maf connections are good . grounds have not been removed . changed my pcv valve back to stock because i put a sti one on and still the same . I'm thinking its the throttle body . i poked it to see if i needed to clean it and now i think it is off. it says 0% when its not closed all the way and 95% wot . whines/ buzzes really loud when the key is on the ON position . i have tried to reset it by unplugging the battery for 30 min and plug it back in but still the same . i will be trying a throttle body next . $100 on ebay for a used one . that is the only thing i can think of . the car is putting out a lot of fuel when i try to start it and my oil is starting to smell like fuel because of it .

01-21-2016, 03:05 PM	#20
j0hnnybk01 Member Join Date: Oct 2013 Drives: Firestorm FR-S Location: Charlotte Posts: 51 Thanks: 4 Thanked 5 Times in 5 Posts Mentioned: 0 Post(s) Tagged: 0 Thread(s)	well i tried my best but can not figure it out . so its at my brothers shop maybe they can figure it out

01-21-2016, 09:36 PM	#22
j0hnnybk01 Member Join Date: Oct 2013 Drives: Firestorm FR-S Location: Charlotte Posts: 51 Thanks: 4 Thanked 5 Times in 5 Posts Mentioned: 0 Post(s) Tagged: 0 Thread(s)	I have to say you are one hell of a guy helping me diagnose this problem ! i never had this much help on a forum before . i will try that when i go up to the shop tomorrow morning . hoping it wont be a fried ecu or need a new harness .

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