When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hi, so I had the engine light on, and I pulled the code “P2A00” which is sensor 1 bank 1, so I replaced and the light went off, but after couple days the light came back on!! With the same code, anyone know something about it?
I took the car to the dealer and they told me is the sensor, they said that sensors from Autoparts are garbage, even if is a Denso. hes trying to make me pay 500 for a Nissan/Denso. Have you heard of this?
Hard to say. For sure you can have this issue on aftermarket coil packs, I don't know about that sensor. On a different note, which sensor did you replace (mass air, upstream o2, downstream 02 or something else)? Have you had any other work done recently on the car? It's possible you can have some kind of air leak causing the code, faulty electrical, etc. Also, there is an interesting post on a sentra forum about the downstream sensor having to be replaced when the code was indicating an upstream sensor fault. Totally different setup I know, but interesting thought.
Hard to say. For sure you can have this issue on aftermarket coil packs, I don't know about that sensor. On a different note, which sensor did you replace (mass air, upstream o2, downstream 02 or something else)? Have you had any other work done recently on the car? It's possible you can have some kind of air leak causing the code, faulty electrical, etc. Also, there is an interesting post on a sentra forum about the downstream sensor having to be replaced when the code was indicating an upstream sensor fault. Totally different setup I know, but interesting thought.
I replaced the Rear Upstream (b1s1). I recently replaced transmition and power steering system, and oil changes.
Dealer keeps telling me its the sensor, they said the heater element on aftermarket sensors are always bad ( I used a Denso from Advance) so, they wanna charge me 500$ for a new sensor and labor!
But before doing that, is there any way to test the sensor that I have to make sure its the sensor, I have the feeling that they just trying to rip me off.
Also, how do I check for vacuum leaks?
Dealer keeps telling me its the sensor, they said the heater element on aftermarket sensors are always bad ( I used a Denso from Advance) so, they wanna charge me 500$ for a new sensor and labor!
But before doing that, is there any way to test the sensor that I have to make sure its the sensor, I have the feeling that they just trying to rip me off.
Also, how do I check for vacuum leaks?
I've seen many cases when new parts arrive and are faulty. You could have a defective sensor, in which case I'd get it swapped with another one. I doubt they'll bench test the sensor to determine if it's faulty or not and if they do, then they can confirm if it is a working unit. If you really want a OEM sensor then the part number is 22693-ZX70A and you can have an outside shop install it instead of the dealer. The O2 Bank 1 Sensor 1 for 7th Gen flat rate runs 0.9 labor hours according to ProDemand. You'll be looking to spend approximately ~$125 in labor alone from an outside shop. Dealerships have different pricing grids and I'm not sure what Nissan's is.
Your Bank 1 Sensor 1 Long Term trims are pretty high so I can see how that triggered a leak code. It's pumping more fuel to compensate for the extra air being sucked in somewhere in the system. MAF intake and O2 output values don't match and O2 is the major sensor when in closed loop. Everything else is around or near stoichometric values.
For the leaks you can use either a smoke machine, a vacuum gauge, or a can of propane. The smoke machine is the easiest but expensive to own unless you run your own business. A Vacuum gauge tells you if you actually have a leak but won't pinpoint where.
The propane test would be the most precise since propane molecules are just big enough to sneak into vacuum leaks. Attach a hose and a metering valve to a propane bottle and let a small amount leak around the intake area while the car is running. Keep an eye on the fuel trim values, especially STFT 1. Trace around the mating areas of the intake manifold and throttle body with the propane and when you see the values change, that's where the leak is. The propane would make the trims seem even richer because it's fuel added to the fire.
Last edited by VeeQue35DE; Jun 7, 2019 at 02:39 PM.
I've seen many cases when new parts arrive and are faulty. You could have a defective sensor, in which case I'd get it swapped with another one. I doubt they'll bench test the sensor to determine if it's faulty or not and if they do, then they can confirm if it is a working unit. If you really want a OEM sensor then the part number is 22693-ZX70A and you can have an outside shop install it instead of the dealer. The O2 Bank 1 Sensor 1 for 7th Gen flat rate runs 0.9 labor hours according to ProDemand. You'll be looking to spend approximately ~$125 in labor alone from an outside shop. Dealerships have different pricing grids and I'm not sure what Nissan's is.
thing is that I already exchange the sensor twice at advance auto parts, I'm really skeptical about being the sensor, I have the feeling is something else. And OEM cost 350$ I dont wanna pay that and get the code again.
thing is that I already exchange the sensor twice at advance auto parts, I'm really skeptical about being the sensor, I have the feeling is something else. And OEM cost 350$ I dont wanna pay that and get the code again.
You could try to cut a deal with your Nissan service adviser, if the $500 fix doesn't get rid of the check engine light then ask for a discount on labor if the same code pops up and it turns out to be something else. If the adviser said that the O2 sensor is the only thing causing the code and nothing else then have him note that on your repair order since it's a legal contract. Otherwise, it was misdiagnosed by the technician and not fair that you should incur the full labor charge because it should've been diagnosed and corrected the first time. I say ask for labor discounts because the part itself isn't expensive but the labor for manifold gaskets is around 2 hours.
I've seen many cases when new parts arrive and are faulty. You could have a defective sensor, in which case I'd get it swapped with another one. I doubt they'll bench test the sensor to determine if it's faulty or not and if they do, then they can confirm if it is a working unit. If you really want a OEM sensor then the part number is 22693-ZX70A and you can have an outside shop install it instead of the dealer. The O2 Bank 1 Sensor 1 for 7th Gen flat rate runs 0.9 labor hours according to ProDemand. You'll be looking to spend approximately ~$125 in labor alone from an outside shop. Dealerships have different pricing grids and I'm not sure what Nissan's is.
Your Bank 1 Sensor 1 Long Term trims are pretty high so I can see how that triggered a leak code. It's pumping more fuel to compensate for the extra air being sucked in somewhere in the system. MAF intake and O2 output values don't match and O2 is the major sensor when in closed loop. Everything else is around or near stoichometric values.
For the leaks you can use either a smoke machine, a vacuum gauge, or a can of propane. The smoke machine is the easiest but expensive to own unless you run your own business. A Vacuum gauge tells you if you actually have a leak but won't pinpoint where.
The propane test would be the most precise since propane molecules are just big enough to sneak into vacuum leaks. Attach a hose and a metering valve to a propane bottle and let a small amount leak around the intake area while the car is running. Keep an eye on the fuel trim values, especially STFT 1. Trace around the mating areas of the intake manifold and throttle body with the propane and when you see the values change, that's where the leak is. The propane would make the trims seem even richer because it's fuel added to the fire.
I have a big problem for that, Im lost about the vacuum lines, I do not know which lines belong to vacuum. I havent been lucky to find any picture or info online.
The vacuum lines are all the lines attached to the intake manifold (main source of pressure Hg / vacuum) but keep in mind that vacuum leaks come from either hoses or gaskets. Also do not mistake the lines from the throttle body for vacuum lines,
The vacuum lines are all the lines attached to the intake manifold (main source of pressure Hg / vacuum) but keep in mind that vacuum leaks come from either hoses or gaskets. Also do not mistake the lines from the throttle body for vacuum lines,
Great, that’s a lot of help, I’ll try that method I hope that’s my problem...
It is, but the dealer said the parts they make for other than Nissan are junk. No sure if I can believe that...
I would not believe a damn thing a Nissan dealer tells me. I'm sure the Denso parts from Advance are just as good if not better than anything the dealer is selling.
Well, I'm still fighting with this issue
I took my car for smoke test and they found no leaks...
my scanner is reading oxygen sensors monitor incomplete, I been driving for miles and miles and I just cant get the drive cycle ready, but now Im getting P0171
RPMs are little high (round 800-100) no car hesitation or rough idle, I have a weird smell but no other symptoms. I had upstream (b1 & b2) oxygen sensors replaced, I cleaned my MAF sensor with proper cleaner. And I just cant find a solution to this problem.
Dealerships keeps telling me is the Oxygen sensor, which I replaced already with a Denso from autoparts, Nissan said Sensors from Autoparts are junk, and that I need to get one from them which is $350!! plus labor... had anyone experienced something like that?
Have you checked the FSM? There is information in the FSM on the P0171 that may be useful. I hope your Nissan dealer is better than the ones I have had experience with. Most of them can't even do the simple repairs correctly.
Have you checked the FSM? There is information in the FSM on the P0171 that may be useful. I hope your Nissan dealer is better than the ones I have had experience with. Most of them can't even do the simple repairs correctly.
Meaning is time to change MAF sensor? I should be able to buy one from advance autoparts and use it without problems right? Or I have to buy it from the dealer? Also, I've read that if the MAF sensor were bad I'll have both banks lean. What do you think?
Meaning is time to change MAF sensor? I should be able to buy one from advance autoparts and use it without problems right? Or I have to buy it from the dealer? Also, I've read that if the MAF sensor were bad I'll have both banks lean. What do you think?
The graph I showed you are the most common fixes for that trouble code and most point towards the MAF, but it's strange that your car is giving you code after code. If the MAF was faulty then it would show in both sensors, like you said, unless the moment that the code is triggered is during a certain driving situation. Then it may be the vacuum actuators on the plenum not moving properly. They're supposed to move according to the needs of the engine. You'd need a scan tool that has a snap shot feature to take images of when the code is triggered and what values pop up at that moment.
Are there any modifications you've done to the engine to change flow? Intake, Exhaust, Headers, block off plates, etc.
The graph I showed you are the most common fixes for that trouble code and most point towards the MAF, but it's strange that your car is giving you code after code. If the MAF was faulty then it would show in both sensors, like you said, unless the moment that the code is triggered is during a certain driving situation. Then it may be the vacuum actuators on the plenum not moving properly. They're supposed to move according to the needs of the engine. You'd need a scan tool that has a snap shot feature to take images of when the code is triggered and what values pop up at that moment.
Are there any modifications you've done to the engine to change flow? Intake, Exhaust, Headers, block off plates, etc.
Nope, any mods... and i do have a scan tool, I can post the freeze data, or wherever is called.
update:
just got a new maf sensor and I tried and... NOTHING! Fuel trims are same, rpms high and everything same
Im about to quit and take it to the stealership!
Nope, any mods... and i do have a scan tool, I can post the freeze data, or wherever is called.
update:
just got a new maf sensor and I tried and... NOTHING! Fuel trims are same, rpms high and everything same
Im about to quit and take it to the stealership!
A better snap shot would be with the vehicle moving and the moment the DTC is triggered. You may need a helper with you if your scan tool doesn't support the function. Erase the DTC and make sure the check engine light is off. Drive around with a partner and have him take a snap shot when the check engine light turns on.
Also, did you perform the fuel ratio relearn when you installed the new MAF?
MIXTURE RATIO SELF-LEARNING VALUE CLEAR : Special Repair Requirement INFOID:0000000005463403
With GST (Generic Scan Tool)
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF.
3. Disconnect mass air flow sensor harness connector.
4. Restart engine and let it idle for at least 5 seconds.
5. Stop engine and reconnect mass air flow sensor harness connector.
6. Select Service $03 with GST. Check that DTC P0102 is detected.
7. Select Service $04 with GST to erase the DTC P0102.
But even after the procedure it might not fix your problem. Like you said earlier, both O2 sensors should show an incorrect value if the MAF were the problem. What's strange is the Open Loop in Fuel Sys1 connected to B1S1 O2 sensor. The PCM still thinks the Bank 1's system is still wrong so it's ignoring fuel correction, which is why it shows values of 0.0% for ST and LT fuel trims1, BUT the 0.915V is rather high for a vehicle @ idle which indicated rich conditions. That kind of voltage is what you'd see if your engine load was around 80-90+%. B2S2 shows that it's trimming back on fuel, which shows that it's running a bit on the rich side. It may be that it's unable to control fuel flow but fuel rail dampers and injectors rarely go bad. This one is a head scratcher for sure... B1 and B2 have their own fuel dampers / regulators.
Your MAF values are good @ idle, within 2.0 - 6.0 grams/sec @ idle, and it should be 7.0 - 20.0 grams/sec @ 2500RPM.
A better snap shot would be with the vehicle moving and the moment the DTC is triggered. You may need a helper with you if your scan tool doesn't support the function. Erase the DTC and make sure the check engine light is off. Drive around with a partner and have him take a snap shot when the check engine light turns on.
Also, did you perform the fuel ratio relearn when you installed the new MAF?
MIXTURE RATIO SELF-LEARNING VALUE CLEAR : Special Repair Requirement INFOID:0000000005463403
With GST (Generic Scan Tool)
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF.
3. Disconnect mass air flow sensor harness connector.
4. Restart engine and let it idle for at least 5 seconds.
5. Stop engine and reconnect mass air flow sensor harness connector.
6. Select Service $03 with GST. Check that DTC P0102 is detected.
7. Select Service $04 with GST to erase the DTC P0102.
But even after the procedure it might not fix your problem. Like you said earlier, both O2 sensors should show an incorrect value if the MAF were the problem. What's strange is the Open Loop in Fuel Sys1 connected to B1S1 O2 sensor. The PCM still thinks the Bank 1's system is still wrong so it's ignoring fuel correction, which is why it shows values of 0.0% for ST and LT fuel trims1, BUT the 0.915V is rather high for a vehicle @ idle which indicated rich conditions. That kind of voltage is what you'd see if your engine load was around 80-90+%. B2S2 shows that it's trimming back on fuel, which shows that it's running a bit on the rich side. It may be that it's unable to control fuel flow but fuel rail dampers and injectors rarely go bad. This one is a head scratcher for sure... B1 and B2 have their own fuel dampers / regulators.
Your MAF values are good @ idle, within 2.0 - 6.0 grams/sec @ idle, and it should be 7.0 - 20.0 grams/sec @ 2500RPM.
yes, I been struggling with this for a couple months. Freaking mechanics around here suck, I really don’t know what to do to at this point. Right now I’m waiting till I don’t get any monitor incomplete make sure that p2a00 code won’t come back. I did the Relearn but the readings were the same.
Here I am, again
last freeze frame, with all the modules complete, P0171 is gone, but i still get P2A00. I Tried the live data while car is moving but my scanner disconnects as soon I car start moving. (U-scan - Actron)
I'll get me a torch to test my o2 sensor.
This is the snap shot when the light came back on. I don't know if that will tell something, I am really stress about it...I will have a long trip soon and Im afraid something will go bad.
This is the snap shot when the light came back on. I don't know if that will tell something, I am really stress about it...I will have a long trip soon and Im afraid something will go bad.
The numbers showing up on your car contradict itself. LTFT being 0 means no adjustment has been made and is running "perfectly" but the ST being in double digits should've moved the LT even a little (0.1) in the 21mins you've been running the car and you still have a P2A00 active code. At this point the best route would be the dealer. Their diagnostic tools should be able to better pinpoint the problem. They also have oscilloscopes to test injector pulse widths and ignition timing box wave patterns, and wideband O2 sensor testers.
The numbers showing up on your car contradict itself. LTFT being 0 means no adjustment has been made and is running "perfectly" but the ST being in double digits should've moved the LT even a little (0.1) in the 21mins you've been running the car and you still have a P2A00 active code. At this point the best route would be the dealer. Their diagnostic tools should be able to better pinpoint the problem. They also have oscilloscopes to test injector pulse widths and ignition timing box wave patterns, and wideband O2 sensor testers.
I did took the car to the dealer this weekend, they replaced the "B1S1 Air/Fuel Ratio Sensor". After I got home I took a look and they replaced that one that is closer to the front bumper, I believe they replaced the wrong one, unless I'm wrong, as I know a 2009 Maxima bank 1 should be the closest to the firewall and bank 2 closest to front bumper, right? Please someone tell me if I'm wrong.
So, I was right, they replaced the wrong sensor :/ I took it back to the dealer and they installed the correct one. So now I have both sensors new (OEM), but engine light still on
Whats next?
LAST REPORT:
MIL STATUS: ON TROUB CODE: P2A00 ABSLT TPS: 5.9% ENG SPEED: 775RPM BARO PRS: 102.0 KPa CALC LOAD: 36.9% MAF: 5.55gr/S COOLANT: 92 DEGC IAT: 58 DEGC IGN ADV: 11.0 DEG ST FTRM1: 14.1% ST FTRM2: -0.8% LT FTRM1: 9.4% LT FTRM2: -3.1% VEH SPEED: 0 KPH ABS LOAD: 27.5% FUEL SYS 1: CLOSED FUEL SYS 2: OPEN DRIVE REL TPS: 3.5% THROT CMD: 5.9% ABS TPS B: 5.9% ACC POS D: 0.0% ACC POS E: 0.0% CAT TEMP11: 300 DEGC CAT TEMP21: 300 DEGC EVAP PURGE: 0.0% EVAP VP: 0.000 Pa CMD EQ RAT: 0.870 O2S B1S2: 0.000V O2S B2S2: 0.850V O2S B1S1: 0.895V EQ RAT B1S1: 0.876 EQ RAT B2S1: 0.993 O2S B1S1: 2.175V MIL TIME: 00:00 CLR DIST: 75 KM CLR TIME 02:48 CLR TRPS: 7 MIL DIST: 0KM FUEL LEVEL: 2.4% VPWR: 14.240V ENG RUN: 16:14
So, I was right, they replaced the wrong sensor :/ I took it back to the dealer and they installed the correct one. So now I have both sensors new (OEM), but engine light still on
Whats next?
LAST REPORT:
MIL STATUS: ON TROUB CODE: P2A00 ABSLT TPS: 5.9% ENG SPEED: 775RPM BARO PRS: 102.0 KPa CALC LOAD: 36.9% MAF: 5.55gr/S COOLANT: 92 DEGC IAT: 58 DEGC IGN ADV: 11.0 DEG ST FTRM1: 14.1% ST FTRM2: -0.8% LT FTRM1: 9.4% LT FTRM2: -3.1% VEH SPEED: 0 KPH ABS LOAD: 27.5% FUEL SYS 1: CLOSED FUEL SYS 2: OPEN DRIVE REL TPS: 3.5% THROT CMD: 5.9% ABS TPS B: 5.9% ACC POS D: 0.0% ACC POS E: 0.0% CAT TEMP11: 300 DEGC CAT TEMP21: 300 DEGC EVAP PURGE: 0.0% EVAP VP: 0.000 Pa CMD EQ RAT: 0.870 O2S B1S2: 0.000V O2S B2S2: 0.850V O2S B1S1: 0.895V EQ RAT B1S1: 0.876 EQ RAT B2S1: 0.993 O2S B1S1: 2.175V MIL TIME: 00:00 CLR DIST: 75 KM CLR TIME 02:48 CLR TRPS: 7 MIL DIST: 0KM FUEL LEVEL: 2.4% VPWR: 14.240V ENG RUN: 16:14
What did they say? Maybe it needs to be driven until the cpu notices and it will reset its self after a good cycle.... ask questions next time lol
What did they say? Maybe it needs to be driven until the cpu notices and it will reset its self after a good cycle.... ask questions next time lol
they cleared the code, after a drive cycle the light came back, Im looking to see if anyone else had/has this kind of issue, since my closer dealer is a joke maybe someone here knows about it.
they cleared the code, after a drive cycle the light came back, Im looking to see if anyone else had/has this kind of issue, since my closer dealer is a joke maybe someone here knows about it.
Do you have an air intake other than stock oem ? Run some fuel injector cleaner and MAF cleaner...maybe one is clogged up....999MP-FSC00P.....start cheap and work you're way up......PCV,Coils, Injectors, MAF.....good luck, and see if the mechanic can check it for free since it came back.
Last edited by BronxSleeperMax187; Aug 4, 2019 at 05:58 AM.
Do you have an air intake other than stock oem ? Run some fuel injector cleaner and MAF cleaner...maybe one is clogged up....999MP-FSC00P.....start cheap and work you're way up......PCV,Coils, Injectors, MAF.....good luck, and see if the mechanic can check it for free since it came back.
No mods in intake or anything, I already run injector cleaner twice, cleaned MAF sensor, PCV replaced, vacuum lines replaced, dealer just changed AF sensors (upstream b1 & b2)
but I still have the light. they did a "diagnosis" again, and they came with 5000$ to fix it lol they said I need to replace my cats.. 5000, seriously?!
Im about to give up and just drive and wait ...
I noted something in last data freeze.
MIL STATUS: ON TROUB CODE: P2A00 ABSLT TPS: 3.5% ENG SPEED: 612RPM BARO PRS: 101.0 KPa CALC LOAD: 23.5% MAF: 2.76gr/S COOLANT: 91 DEGC IAT: 56 DEGC IGN ADV: 14.0 DEG ST FTRM1: 14.1% ST FTRM2: 0.8% LT FTRM1: 9.4% LT FTRM2: -3.1% VEH SPEED: 0 KPH ABS LOAD: 17.3% FUEL SYS 1: CLOSED FUEL SYS 2: CLOSED REL TPS: 3.5% THROT CMD: 3.1% ABS TPS B: 3.5% ACC POS D: 0.0% ACC POS E: 0.0% CAT TEMP11: 164 DEGC MECHANIC AT DEALER SAID CAT TEMPS WERE DIFFERENT AND THEY SHOULD BE THE SAME, BUT MY SCANNER SHOWS SAME TEMP. CAT TEMP21: 164 DEGC EVAP PURGE: 0.0% EVAP VP: 0.000 Pa CMD EQ RAT: 0.870 O2S B1S2: 0.000V is this normal? also, where is O2S B2S1? O2S B2S2: 0.670V O2S B1S1: 0.740V EQ RAT B1S1: 0.859 EQ RAT B2S1: 1.004 O2S B1S1: 2.270V MIL TIME: 00:00 CLR DIST: 124 KM CLR TIME 03:17 CLR TRPS: 3 MIL DIST: 0KM FUEL LEVEL: 38.0% VPWR: 14.240V ENG RUN: 17:57
