01 pathfinder sensor trouble cam shaft pos and max airflow

[jclaxcoach]

ses light went on and i had it diagnosed. replaced the cam shaft position sensor and was told if it came back on i would need a max air flow sensor. it is on order. can someone help with a diagram of where this is? has anyone had this problem before? How do you get ses off after it is switched out? any help would be useful.thanks

[bigun22]

I had both O2 sensors replaced when the SES light came on. The problem was fixed for a week. The light came back on and they replaced the O2 sensors again, free this time. The light went off and then came back on again they replaced the sensora AND the MAFS and a year later no problems. They told me that the MAFS regulated the fuel and if it went bad the O2 sensors would burn out. They never mentioned how this sensor had any thing to do with the Valve sensor, dosen't make sense to me why the air sensor would relate to the valve sensor. maybe because it's $400.

[NISTECH]

Ok Thread starter read my sticky on intake sensor replacement. I think your getting a load of bull from your shop.

Bigun22. If you have a pathfinder or qx4 built after 98; When the rear O2's are replaced the ECM is suppose to be reprogrammed to prevent the O2 heater from coming on at full intensity on initial fire up so the O2 wont fry from moinsture build up on it. The on cycle amperage is stagered on to help evaporate the moisture on it with the new ECM program. The airflow meter was not the cause. I fell you have just been fortunite to not have the O2 burn up yet. It is more common to happen in the dead of winter when moisture content in the air is greater.

[bigun22]

Yes the dealer said the ECM was reprogramed to prevent burn up. This was done before I bought the car. I have a 2001 3.5L Path. Yes the problem was last winter. They also told me they had a bad run of O2 sensors and a lot of them had to be replaced. I joined this forum yesterday because I am having a P1140 code problem right now. A friend checked the code for me. I bought a Equus 3100 this week and I am going to check things for myself. The last SES fiasco cost me almost a grand. Can you tell me what would be a good shop manual to buy. Sensors, codes and where they are located. Thanks

[NISTECH]

The only manual I could recommend for a nissan product is a factory service manual. The other options dont seem to come close to being thorough enough. The only alternative service information resource I have found that has almost as much info is alldata. It is a CD/Internet based program you can purchase on a subscription basis.

You should read my sticky at the top of this forum for an indepth explination about your code and what can cause it.

[bigun22]

The Alldata site looks very comprehensive. I did read the stickey, I think I have the P1140 under control. I got the reader because I am in this for the long run. Just this one event will pay for the reader.Thanks for your help.

[jclaxcoach]

repalced the mafs sensor and the ses light came back on..... very frustrating. have an appt. w/ nissan dealer for another diagnosis and wandering if anyone has advece that may help get me out of this reoccuring ses problem w/o changing every sensor in the whole vehicle?

[NISTECH]

What is your current code for?

[jclaxcoach]

don't have a code yet. I have to get a diagnosis from nissan dealer next sat. i'll let you know what comes up. This all started when i took it to a shop that told me bank 1 o2 sensor and replaced it only to have the light come up again......... so in it went to nissan where i got a cam pos sensor and was told it needed a mafs if the light went back on. now i have done all that and the light is back on and this is getting expensive. just thought that there may be a reason everything is going or if there is something that is tripping all the sensors????? I am out of ideas so thats why i'm going to the big computer at nissan dealer. any help would be useful.

[NISTECH]

If you have an autozone in your area go into them and have them just pull your code. They do that for free.

[jclaxcoach]

OK I took your advice and went to autozone. P0158 bank 2 sensor O2 sensor high volts ....... and..... P0160 O2 sensor CKT no activity bank 2 sensor 2. I'm not sure what this all means or if the hand held diagnostic is giving a false reading but i'm beginning to think that i am the most unlucky sensor failing nissan owner on the planet. What is the real problem? If you can help please let me know.bill

[NISTECH]

I have to wonder if they actually did reprogram your ECM. This should not be reoccuring. I have yet to see a return visit on the ones I have done. The sensors are not the real problem but are probably failin now. I think you should follow up with the Nissan diag. If at all possible gather up all old reciepts for repairs and go to the dealer that did the repair with the reprogram. Make sure you go over with them this is a reoccuring problem and that you would like thier nissan master tech to take a look at it. Also tell the advisor you want the tech to review your prior repair records. If you dont stress this the tech working on the car will make quick diag thinking its a first time occurance.

[jclaxcoach]

Went to nissan mechanic today. Their computer read an o2 sensor driver side behind the cat. The ecm was also reset for the first time at no charge. I was told that the ses light may not come up again with the ecm reset and that the o2 sensor behind the cat had no real bering in the performance on the vehicle......... If the ses comes up again I will need to replace the sensor before I get the car inspected next year. Can anyone see a reason to be worried........ I still feel a little uncomfortable if the ses comes on again that this problem will start another chain reaction of sensor problems..... should i be worried?

[NISTECH]

no you shouldnt be worried. As he said it has nothing to do with engine control. It is only there for diagnostic purposes of the cat. To meet Federal OBDII standards that the car can test it self.