P0158 and P0159 on a 2001 Pathfinder

[Ridge Racer]

So the day before emissions test, the SES light comes on in our 2001 Pathfinder. Emissions tester said codes: P0158 and P0159 came up.

We have run 2 tankfulls of 87 octane gas through (normally only put in 93 octane, but thought we'd try the cheaper stuff) and I am wondering if that would cause something like this.

I am also wondering if anyone has run into this issue and can tell me what all needs to be checked / replaced.

Thank you!

[NISTECH]

There is a nissan technical service bulliten on this. What needs to be done is both rear O2's replaced and the ECM flash programed to not turn the O2 heaters oin so soon. It has minimal to do with the fuel your using, what its from is The moisture that builds in your exhaust over night. When you fire up the car the O2 heaters come on almost immediatly, if they are covere in moisture it burns the heater up and you get those codes. The fix Is to replace the O2's and reprogram the ECM so that it will gradually turn the heaters on to help dry up the moisture without frying them. Or not turn them on till the engine temp is at a level it knows they would no longer be covered in moisture. I have heard both senarios from engineering but the end result is the ECM reprogram changes/alters the O2's heater turn on point.

[Ridge Racer]

hmmm..... flashing the ECM. Sounds racy!!

Seriously though - I'm guessing that's not something I'll be able to do in my garage with a laptop and a couple of paper clips, right?

Is this something I am going to have to ***shudder*** - pay someone else to do?

Thank you!

[NISTECH]

no you cant do it in your garage, you could try to save some money buy putting the O2's in your self, which by the way is a real pain in the rear and may send you to paying someone else to finish it. All the clips on the harness are what makes it miserable, Acouple of them are in rediculas locations and know human hand can come anywhere close to them do to its tight location. A dealer will have to do the reprograming though.

[Ridge Racer]

Man! You ain't kiddin' about those @%**!!!! clips!! I replaced the one that the code suggested - (bank 2 sensor 2) the driver's side post catalytic converter. Getting to the O2 sensor was a breeze. Getting the old clips out required a pair of wire cutters and I had to have a third joint surgically implanted between my wrist and elbow!

I drove the truck around for about an hour afterwards, stopping and shutting it down every 10 minutes or so - hoping the SES light would turn off. No luck that way, so I disconnected the battery overnight, reconnected it before I drove to work and the light stayed off. Good thing too - since my tags expire at the end of April and yesterday was the last day I could get the emissions test done before the truck became 'illegal!'

So - since the SES light has not come back on - is it safe to assume that the bank 1 sensor 2 is still ok? Would you recommend that I go ahead and have the Nissan dealer reprogram the ECM? Is it a fairly common issue? The dealers here want between $85 and $120 to do that job...
Modified by Ridge Racer at 10:14 AM 4/30/2005

[NISTECH]

sensor one may be ok but you need to get the program done so it wont burn them out.

[jliaou]

I think I am the first to figure this problem out. About 1.5 years ago I ran into funny problem codes and this same stalling problem. I took it in 3 times to the same Nissan Dealership and they couldnt' figure it out. They kept giving me new "fixes" to try. I finally took it to an independent repair place and the guy figured it out. The Turbine Revolution Sensor on top of your Transmission is probably faulty and is leaking transmission fluid through it. Because of this leak, you will probably get funny problem codes down the road here. The transmission fluid flowd down the wiring harness of this sensor into a whole host of other harnesses, triggering Intake sensor issues, O2 sensor issues, etc. The stalling is due to the low transmission fluid. Check your transmission fluid. If it's low, then fill it up. Your problem should go away. Good luck. Let me know if this fixes the problem. BTW, the metal housing blocks the visibility of the transmission fluid on the ground until the leak gets severe, like mine did. Good luck and please repost to let me know.

~Blessings.

[NISTECH]

I think I will only post in one of your repetitive posts here.

Nissan's generally dont have "wicking" problem. That is what your saying happened. Not saying it didn't happen cause I can actually see it happening with the new harnesses nissan is using, and the poorly made plastic sensors. This has been the problem with the can sensors getting oil in the connector area on several models.

Wicking was more common to GM products in the early 90's do to well sealed connectors ,something nissan has just begun in the last few years or so. Due to this its likely the reason the dealer didnt find the problem as line techs generally only have experiance with that specific vehicle makers products. Where as the independant has a more generalized but cross experiance with many makes of cars.

After your post I to will now look at this sensor for problems as it dosent suprise me since the sensor is very similar to the cam and crank sensors I have been seeing this prblem on.

[penbed51]

So,I had PO160 code.When I read code I cleared it and CEL stayed off.What can I expect now?

Mine is 1999.5 Pathfinder.Bought this car new,only has 64,000 miles and has been troublefree.Is she starting to show her age?

[Finny]

Looks like I'm digging up bones here but hopefully someone can help. I am getting a CEL and my code is P0140.

P0140 O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 2)

This is a 2001 QX4 with about 120k. I was looking at the service history on this vehicle and the left rear sensor was replaced at around 60k and the ECM was reflashed.

Now for my questions:

Since the ECM was reflashed does this mean it does not need to be done again?

Have any of you sucessfully replaced this sensor... was it worth doing it yourself?

Any other advice?

[slownslurious]

Mine is throwing P1167 and I can't find what the hell this code means anywhere.

I'm pissed cause its been doing this since 57k and its got 86k on it now (in like 9 months) and I think it may need reprogrammed, which I guess coudl have been done under warranty with <80k.

*sigh*

[nheitz]

Man! You ain't kiddin' about those @%**!!!! clips!! I replaced the one that the code suggested - (bank 2 sensor 2) the driver's side post catalytic converter. Getting to the O2 sensor was a breeze. Getting the old clips out required a pair of wire cutters and I had to have a third joint surgically implanted between my wrist and elbow!

x2... If I did it again I would just cut the wires and both ends, leave those clips in place, & zip tie the new one to something else.

[nheitz]

I think I am the first to figure this problem out. About 1.5 years ago I ran into funny problem codes and this same stalling problem. I took it in 3 times to the same Nissan Dealership and they couldnt' figure it out. They kept giving me new "fixes" to try. I finally took it to an independent repair place and the guy figured it out. The Turbine Revolution Sensor on top of your Transmission is probably faulty and is leaking transmission fluid through it. Because of this leak, you will probably get funny problem codes down the road here. The transmission fluid flowd down the wiring harness of this sensor into a whole host of other harnesses, triggering Intake sensor issues, O2 sensor issues, etc. The stalling is due to the low transmission fluid. Check your transmission fluid. If it's low, then fill it up. Your problem should go away. Good luck. Let me know if this fixes the problem. BTW, the metal housing blocks the visibility of the transmission fluid on the ground until the leak gets severe, like mine did. Good luck and please repost to let me know.

~Blessings.

I'd say his O2 sensors were actually bad & not caused by this. They don't even go near that harness you're speaking of.

That being said, I noticed a couple of drops of ATF on my garage floor the other day under the passenger side running board about midway back... which really confused me. I noticed ATF all around that heat shield you're referring to & when I searched I found several people who've had this problem. The turbine revolution sensor leaks & ATF gradually makes it's way down the harness to this area that all of the harnesses plug in to. The fix... The entire transmission has to be dropped to change this one sensor because it's located on top of the transmission. I'm sure that's cheap. I took off my heat shield & cleaned everything as best as I could but I'm thinking about ignoring it. Those couple of drops were the first & my ATF has never been low... I check it monthly. Where's that Nissan Tech? Any harm in ignoring it?