It came on this morning while driving to work!

Any Ideas?

Car has been running great without a problem .

2000 SE w/45000 miles

 

I would suggest trying a search on resetting your ECU. There are a couple of threads the are helpful. Good luck.

 

Most likely scenario would be a failed O2 sensor. I've had a couple (64K miles). Depending on the relationship you have with your dealer they may even fix under Nissan's 'Good Will' program.

Good luck!

 

How much are the sensors?

 

I'm really not sure, as Nissan paid for mine. Sorry I can't be more helpful.

 

I just had my O2 sensors replaced under warranty (5 years and 75,000 miles for emission equipment, I believe). The error codes from the ECM were P0138 and P0140. I had a friend with a handheld diagnostic tool to get the codes for me.

Bank 1 sensor 2 is the sensor back closer to the catalytic converter. It is not used under normal conditions, so it doesn't effect your gas mileage. I think it's just a backup to protect the cat if the other sensor fails. Unfortunately the service bulletin is saying that the ECM needs a software update, "Reprogramming of the vehicle's ECM to the New ECM Data P/N may also be needed to help prevent incidents from reoccurring (this revision contains ECM data which has been improved over the previously published ECM data). "

Here is a link for the TSB. Give this to your dealer. Knowledge is power.

http://www.nissan-techinfo.com/nissa...7.asp?mscssid=

 

Autozone told me it was an air leak P0171 anyone have any details on what this contains in detail?

Would a K&N drop-in cause this problem?

 

My SES came on a few months ago but was the gas cap (it wasn't tight)
try this man... new sensor is around $200... i was scare because my car has only ~17k miles on it!!

 

Mine does the exact same thing this summer!!

After 2 week off no-use (bike's accident), I started it and 30 sec later SES came out!!

Delaer change the back O2 sensor (mine was under warranty)

Yes it could be the gas cap!! Go full it and make sure it's tight!!

 

The gas cap is tight!!!!

That was the first thing I did.

I reset the ECU and the light is gone for now so we will see what happens.

 

If it's the O2 sensor. The SES light will come out shortly!

 

Mines been on for a week, 00 w/ 51k, it goes into Nissan next friday.

BTW, Thanks for the TSB info.

 

Worth a check at a dealer or someone with a computer readout tool. CES light comes on with O2 sensor problem but also with low emission containment, ie gas cap not tight OR leak in the evap system. The computer monitors pressure in the gas tank vapor system based on pressure loss and number of trips. Then turns on the light. Cracks in the cansiter brought mine on. It went off after awhile and came back on again. Replaced the canister and all's been fine.