P2A00 - A/F Sensor Circuit Range/Performance (bank 1 sensor 1)

jwick · 08-20-2014, 09:07 AM

I know this is not technically a FI problem but I'm opening it here because I am only looking for FI based feedback on the code.

What's happened:
- In early July the referenced code was thrown. The car had ~46k miles on it so I figured it was probably a bad O2 and ordered the new part. Deleted the code and babied it back and forth to work until the sensor came in. I would say I put between 150-200 miles on the car after I cleared the code.
- Receive the new sensor and replaced it.
- Drove for 400-500 miles and the code came back yesterday. (so roughly 600 miles between codes and a new sensor)

How it runs:
- Car runs exactly as it always has since my tune (roughly 2000 miles). Idles fine, closed loop and open loop acting as normal.

What I've checked:
- Sensor plug is firmly seated into its socket
- Wiring was good when I put it in and I covered it with a Thermo-tec sleeve to make sure heat was not an issue (it is the O2 sensor that basically sits less than a foot from the cold side of the turbo). I can't see there being any melting issues on the harness. Item to note I had not wrapped the original sensor when I did the turbo install and when I removed it the wiring for the sensor still looked perfect.
- Checked all silicon couplers on the intake piping, no leaks I can see
- Checked half the triangle flange on the header, can't currently see the other half without dropping the turbo. Don't see any areas where I think the gasket has blown out.
- I monitor fuel pressure all the time and it's steady, no drops or erratic behavior
- Innovate shows both closed and open loop AFRs are unchanged
- I did not have time to log idle and closed loop AFRs from UpRev last night but I'll go that just to make sure but last time (pre-sensor replacement) both sensor 1 readings were almost spot on

Questions:
- The obvious one, any ideas on what the issue might be?
- Does the car use this sensor for anything besides closed loop trims?
- The previous questions is based on how concerned should I be about the code if there are no other codes popping up? In open loop (i.e. under acceleration) shouldn't the car use the program defaults my tuner set and not cause any issues?
- One of the possible causes listed with that code is fuel pressure/fuel injectors. Wouldn't I get other codes with it if I had a faulty injector? Also wouldn't the car run a little rough if there were fueling issues?

ANMVQ · 08-20-2014, 09:11 AM

Well the first thing I thought was a pre sensor air leak? You looked at that gasket already but can see the whole thing ? Can you get your hands on a mirror stick and look up there? you can also try sticking a piece gasket down there and rev the car and see if there is any exhaust coloring on it? Paper might work too but not sure if it catch fire with the exhaust temps( Piping)

you can also use the soap water test on the intake pipes , Spray the connecters down ?

jwick · 08-20-2014, 09:22 AM

Quote:

Originally Posted by ANMVQ

Well the first thing I thought was a pre sensor air leak? You looked at that gasket already but can see the whole thing ? Can you get your hands on a mirror stick and look up there? you can also try sticking a piece gasket down there and rev the car and see if there is any exhaust coloring on it? Paper might work too but not sure if it catch fire with the exhaust temps( Piping)

you can also use the soap water test on the intake pipes , Spray the connecters down ?

I tried my best with my mirror but there is just too much stuff in the way. It came on last night on my drive home and I didn't have enough time to start tearing the car apart and have it back together for work this morning.

The gasket in question is post sensor. So unless there is a leak at the header itself, any pre-sensor leak would have to be in the intake piping. Correct me if I'm wrong but the leak would also need to be post-MAF sensor. Also if I had a leak post-sensor I would expect to pick up a change in my Innovate which is in the downpipe.

The gasket/paper idea sounds good. I'll have to see if I can get something in there.

ANMVQ · 08-20-2014, 10:16 AM

it could also be post-MAF sensor yes. Could be the MAF itself also? Another thing I was reading was it could be a bad coil pack?
" When the engine mis-fires, it sends a slug of unburned fuel and air into the exhaust stream that flows down to the sensor and can throw a p2a00 code"
From Motordyne.

jwick · 08-20-2014, 11:18 AM

Quote:

Originally Posted by ANMVQ

it could also be post-MAF sensor yes. Could be the MAF itself also? Another thing I was reading was it could be a bad coil pack?
" When the engine mis-fires, it sends a slug of unburned fuel and air into the exhaust stream that flows down to the sensor and can throw a p2a00 code"
From Motordyne.

I would expect a mis-fire to have other codes associated with it.

ANMVQ · 08-20-2014, 12:14 PM

Might not be a complete misfire p300 tho. ? IDK just something else I was reading. :/

jwick · 08-20-2014, 01:28 PM

Anybody with knowledge of what the ECU sensor uses the fuel trim sensor for outside of closed loop?

I guess in simple terms, in addition to any solutions, I'm asking if there would be any open loop safety (engine) related to that code?

jwick · 08-20-2014, 01:29 PM

Quote:

Originally Posted by ANMVQ

Might not be a complete misfire p300 tho. ? IDK just something else I was reading. :/

I've had the random misfire come up in the past but I had the sensitivity turned down because it was related to high idle rpms and lightweight aftermarket flywheel making a bunch of noise.

Jordo! · 08-20-2014, 01:47 PM

Check for vac leaks by spraying carb cleaner all along the intake tract, after the MAF, up to and around the IM gasket -- no change in idle means no leaks. You'll have to get it on a lift to check around the O2 bung on the header.

If no evidence of any vac leaks then do some datalogging with cipher.

Confirm similar voltage on bank and 2 MAF's and also log AFR and AF voltage readings on both primary O2's (note that weirdly cipher sometimes labels both as "bank 1"), fuel trims, and heater sensor correction %.

Wildly different voltage between the banks points to one sensor or the wires (if you have extenders) or both being bad -- based on that code, Bank 1 should be skewing way lean compared to Bank 2. You will also see massive fuel correction when that happens as the ECU tries to catch itself and keep on target.

Also note heater correction %: Low correction (say up to 30%) means normal warm up; high correction (close to 100%) means bad sensor, bad wires or both (usually bad sensor).

I just had similar problem, same code (same bank, in fact) eventually started getting constant low heater code for that bank.

New sensor already ordered.

If you find no evidence of different voltages, corrections etc, then its random and meaningless... however, I'm betting on a bad Bank 1 upstream O2.

jwick · 08-20-2014, 06:46 PM

Quote:

Originally Posted by Jordo!

Check for vac leaks by spraying carb cleaner all along the intake tract, after the MAF, up to and around the IM gasket -- no change in idle means no leaks. You'll have to get it on a lift to check around the O2 bung on the header.

If no evidence of any vac leaks then do some datalogging with cipher.

Confirm similar voltage on bank and 2 MAF's and also log AFR and AF voltage readings on both primary O2's (note that weirdly cipher sometimes labels both as "bank 1"), fuel trims, and heater sensor correction %.

Wildly different voltage between the banks points to one sensor or the wires (if you have extenders) or both being bad -- based on that code, Bank 1 should be skewing way lean compared to Bank 2. You will also see massive fuel correction when that happens as the ECU tries to catch itself and keep on target.

Also note heater correction %: Low correction (say up to 30%) means normal warm up; high correction (close to 100%) means bad sensor, bad wires or both (usually bad sensor).

I just had similar problem, same code (same bank, in fact) eventually started getting constant low heater code for that bank.

New sensor already ordered.

If you find no evidence of different voltages, corrections etc, then its random and meaningless... however, I'm betting on a bad Bank 1 upstream O2.

Haven't done the intake check yet but I went ahead and logged considering I was in the car waiting for it to cool down enough to turn it off.

Seems like everything is in order except the heater correction. Bank 1 is running 25% lower than bank 2. I just replaced the O2 sensor less than two tanks of gas ago. Is it possible the additional heat from the turbo, which is only a foot away (physical distance, flow piping its probably 18"), is causing the drop in heater temp on that side?

BBRSpeedWorks · 08-20-2014, 06:55 PM

I was thinking about just turning off my rear of sensors. That's what I did on my 350z and never had a problem

Jordo! · 08-20-2014, 06:59 PM

Quote:

Originally Posted by jwick

Haven't done the intake check yet but I went ahead and logged considering I was in the car waiting for it to cool down enough to turn it off.

Seems like everything is in order except the heater correction. Bank 1 is running 25% lower than bank 2. I just replaced the O2 sensor less than two tanks of gas ago. Is it possible the additional heat from the turbo, which is only a foot away (physical distance, flow piping its probably 18"), is causing the drop in heater temp on that side?

In don't think so -- that's all based on a wire's voltage for a wire dedicated to warming up the sensor.

The heat could be killing the wire itself tho and causing misreads -- what are the values for each bank? Lower values mean the sensor is getting up to temp quickly (unless its a misread), higher values mean it can't maintain operating temps.

Are the O2 voltages and AFR'd different for each bank too?

jwick · 08-20-2014, 07:03 PM

Quote:

Originally Posted by Jordo!

In don't think so -- that's all based on a wire's voltage for a wire dedicated to warming up the sensor.

The heat could be killing the wire itself tho and causing misreads -- what are the values for each bank? Lower values mean the sensor is getting up to temp quickly (unless its a misread), higher values mean it can't maintain operating temps.

Are the O2 voltages and AFR'd different for each bank too?

Bank 1 is 28.8 and bank 2 is 36.

AFRs are basic spot on and match the innovate. Which parameter is AFR voltage as I'm not sure I logged that one?

The wiring I pulled out, which had no heat protection, looked perfect. I wrapped the whole sensor cable in thermo-tec sleeve before I put the new one in so I don't see how heat could be an issue. I also have the crossover turbo piping header wrapped and the turbo bagged. I don't think its heat on the wires.

jwick · 08-20-2014, 07:04 PM

Quote:

Originally Posted by BBRSpeedWorks

I was thinking about just turning off my rear of sensors. That's what I did on my 350z and never had a problem

Unfortunately this is the fuel trim sensor not the post cat sensor.

BBRSpeedWorks · 08-20-2014, 07:39 PM

Ooo sorry my fault..

08-20-2014, 09:07 AM	#1 (permalink)
jwick A True Z Fanatic Join Date: Dec 2010 Location: Houston Posts: 14,532 Drives: '10 G37 6MT Rep Power: 2465056	P2A00 - A/F Sensor Circuit Range/Performance (bank 1 sensor 1) I know this is not technically a FI problem but I'm opening it here because I am only looking for FI based feedback on the code. What's happened: - In early July the referenced code was thrown. The car had ~46k miles on it so I figured it was probably a bad O2 and ordered the new part. Deleted the code and babied it back and forth to work until the sensor came in. I would say I put between 150-200 miles on the car after I cleared the code. - Receive the new sensor and replaced it. - Drove for 400-500 miles and the code came back yesterday. (so roughly 600 miles between codes and a new sensor) How it runs: - Car runs exactly as it always has since my tune (roughly 2000 miles). Idles fine, closed loop and open loop acting as normal. What I've checked: - Sensor plug is firmly seated into its socket - Wiring was good when I put it in and I covered it with a Thermo-tec sleeve to make sure heat was not an issue (it is the O2 sensor that basically sits less than a foot from the cold side of the turbo). I can't see there being any melting issues on the harness. Item to note I had not wrapped the original sensor when I did the turbo install and when I removed it the wiring for the sensor still looked perfect. - Checked all silicon couplers on the intake piping, no leaks I can see - Checked half the triangle flange on the header, can't currently see the other half without dropping the turbo. Don't see any areas where I think the gasket has blown out. - I monitor fuel pressure all the time and it's steady, no drops or erratic behavior - Innovate shows both closed and open loop AFRs are unchanged - I did not have time to log idle and closed loop AFRs from UpRev last night but I'll go that just to make sure but last time (pre-sensor replacement) both sensor 1 readings were almost spot on Questions: - The obvious one, any ideas on what the issue might be? - Does the car use this sensor for anything besides closed loop trims? - The previous questions is based on how concerned should I be about the code if there are no other codes popping up? In open loop (i.e. under acceleration) shouldn't the car use the program defaults my tuner set and not cause any issues? - One of the possible causes listed with that code is fuel pressure/fuel injectors. Wouldn't I get other codes with it if I had a faulty injector? Also wouldn't the car run a little rough if there were fueling issues? __________________ '10 G37T 6MT Graphite/Graphite - BP - G37T Build

08-20-2014, 09:11 AM	#2 (permalink)
ANMVQ A True Z Fanatic Join Date: Mar 2011 Location: Framingham MA Posts: 2,732 Drives: 2014 Q50 AWD Rep Power: 19	Well the first thing I thought was a pre sensor air leak? You looked at that gasket already but can see the whole thing ? Can you get your hands on a mirror stick and look up there? you can also try sticking a piece gasket down there and rev the car and see if there is any exhaust coloring on it? Paper might work too but not sure if it catch fire with the exhaust temps( Piping) you can also use the soap water test on the intake pipes , Spray the connecters down ? __________________ 14 Q50 AWD, ARK, ECUTEK (SEB), Takda,

08-20-2014, 10:16 AM	#4 (permalink)
ANMVQ A True Z Fanatic Join Date: Mar 2011 Location: Framingham MA Posts: 2,732 Drives: 2014 Q50 AWD Rep Power: 19	it could also be post-MAF sensor yes. Could be the MAF itself also? Another thing I was reading was it could be a bad coil pack? " When the engine mis-fires, it sends a slug of unburned fuel and air into the exhaust stream that flows down to the sensor and can throw a p2a00 code" From Motordyne. __________________ 14 Q50 AWD, ARK, ECUTEK (SEB), Takda,

08-20-2014, 12:14 PM	#6 (permalink)
ANMVQ A True Z Fanatic Join Date: Mar 2011 Location: Framingham MA Posts: 2,732 Drives: 2014 Q50 AWD Rep Power: 19	Might not be a complete misfire p300 tho. ? IDK just something else I was reading. :/ __________________ 14 Q50 AWD, ARK, ECUTEK (SEB), Takda,

08-20-2014, 01:28 PM	#7 (permalink)
jwick A True Z Fanatic Join Date: Dec 2010 Location: Houston Posts: 14,532 Drives: '10 G37 6MT Rep Power: 2465056	Anybody with knowledge of what the ECU sensor uses the fuel trim sensor for outside of closed loop? I guess in simple terms, in addition to any solutions, I'm asking if there would be any open loop safety (engine) related to that code? __________________ '10 G37T 6MT Graphite/Graphite - BP - G37T Build

08-20-2014, 01:47 PM	#9 (permalink)
Jordo! A True Z Fanatic Join Date: May 2010 Location: nirvana Posts: 6,394 Drives: 2023 NATM Rep Power: 418	Check for vac leaks by spraying carb cleaner all along the intake tract, after the MAF, up to and around the IM gasket -- no change in idle means no leaks. You'll have to get it on a lift to check around the O2 bung on the header. If no evidence of any vac leaks then do some datalogging with cipher. Confirm similar voltage on bank and 2 MAF's and also log AFR and AF voltage readings on both primary O2's (note that weirdly cipher sometimes labels both as "bank 1"), fuel trims, and heater sensor correction %. Wildly different voltage between the banks points to one sensor or the wires (if you have extenders) or both being bad -- based on that code, Bank 1 should be skewing way lean compared to Bank 2. You will also see massive fuel correction when that happens as the ECU tries to catch itself and keep on target. Also note heater correction %: Low correction (say up to 30%) means normal warm up; high correction (close to 100%) means bad sensor, bad wires or both (usually bad sensor). I just had similar problem, same code (same bank, in fact) eventually started getting constant low heater code for that bank. New sensor already ordered. If you find no evidence of different voltages, corrections etc, then its random and meaningless... however, I'm betting on a bad Bank 1 upstream O2. __________________ Enjoy it. Destroy it. Last edited by Jordo!; 08-20-2014 at 01:54 PM.

08-20-2014, 06:55 PM	#11 (permalink)
BBRSpeedWorks Premium Member Join Date: Dec 2013 Location: Ft. Stwart Posts: 366 Drives: 370z,350z,300z,talon Rep Power: 12	I was thinking about just turning off my rear of sensors. That's what I did on my 350z and never had a problem

08-20-2014, 07:39 PM	#15 (permalink)
BBRSpeedWorks Premium Member Join Date: Dec 2013 Location: Ft. Stwart Posts: 366 Drives: 370z,350z,300z,talon Rep Power: 12	Ooo sorry my fault..

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