Hi All,

05 5AT Coupe with 95,000 miles. Car is stock except for a Ztube and a K+N drop in filter.

This is the history so far.

Got the SES light. Code was the P1273. Brought to mechanic who replaced the A/F sensor on Bank 1, Sensor 1. In about 30mi the SES light came back on

Of course tried resetting the computer a couple of times. I also cleaned the MAF before bringing it back to the mechanic. Car is now displaying both a P1273 and P1283 codes.

Second time around, the mechanic spent quite a bit of time checking the cats and for leaks in the intake and exhaust. They came away with nothing. He also cleaned the MAF and drove it for about 30 mi. Gave it back without the light on hoping he got it with the MAF cleaning. However after driving another 10 miles after picking it up, the light has come back.

So what is next? Any other ideas before replacing the Bank 1 sensor 2 in the manifold?

From previous posts it could also be an issue with the factory cats? Although it seems that most who get these two codes together are running HFC's or testpipes. Mine are still stock.

Thanks for any help/ideas

 

You're correct those codes are usually related to running Test Pipes or HFCs. If it is just the light that bothers you we offer 02 extenders will will likely eliminate the code, BUT this WILL NOT fix the actual problem that is causing the light. LINK

Have you ever had a bad misfire? If so this could kill the cats.

More than likely you either have an extremely rich condition or bad cats (which rich condition would eventually lead to). Have you changed the plugs recently?

I suggest having your mechanic visually inspect the internals of the cats, it should be obvious if they have failed, and also change your spark plugs if you haven't recently.

Let me know if I can help you with anything.
-Rob

 

Thanks Rob

I will look into the extenders as an option...knowing of course that it will not fix anything but the light. They will also allow me to pass an inspection right?

I am not aware of any misfire. The car has never run poorly. The spark plugs have not been changed (at 95k now). We are checking milage now, but it has not seemed to have dropped at all as of late. Car seems fine.

The mechanic has mentioned the cats multiple times and I believe inspected them, but I will quiz him a bit more about how far he went with that.

The upsteam O2 sensor is pretty cheap at Amazon (Bosch), I may have them replace the bank 2 sensor. That way I will have two new ones in there before we spend more time troubleshooting.

 

Passing inspection varies based on your local inspection procedures. If they just check for codes then yes extenders *should* make you pass.

Upstream? Those aren't upstream codes. Changing the Upstream 02s would not have an affect on your issue. Those codes are related to Catalyst efficiency which is checked by the downstream sensors in the middle of the cats.

-Rob

 

Hi Rob

P1273 INFINITI - Air Fuel Ratio (A/F) Sensor 1 Lean Shift Monitoring Bank 1
P1283 INFINITI - Air Fuel Ratio (A/F) Sensor 1 Lean Shift Monitoring Bank 2

Isn't the O2 sensor 1 in the exhaust manifolds right where they merge into a single tube? Sensor 2 is in the cats?

 

Can anyone confirm if I am messing with the right o2 sensors based on these codes (upstream)? I have Bosch P/N 15667 in my hand ready to go into Sensor 1. bank 2.

Thanks

 

Subscribed, I am having the same problem except I have HFC. The dealer replaced the O2 sensor.

 

Sorry I was wrong, You are correct those codes are referring to the #1 Upstream sensors. I'm stumped, the only other thing I can think of is maybe a vacuum leak or exhaust leak before the sensors.


You can try the 02 bung extenders we offer, if that doesn't work, you will likely need a tune to eliminate the code.

-Rob

 

Im throwing the same codes. Although im tt my widebands r showing that im not leaning out. Guess ill just have my tuner fix it

 

Thanks, but since I am under warranty I am going back to the dealer next week to see what they say. If they can't fix it or blame my aftermartket parts, my next step is to get it tune since I wanted to get it done.

 

Stock except for the K+N and ZTube and replacing both upstream O2 sensors did not fix these codes. Will scan this weekend to confirm they are the same ones. Really fustrating.

 

I had the same issue, replaced all 4 sensors, finally just got it tuned and never came back!

 

When you say you got it tuned, does that mean tuning out the code so the light doesn't showup?

Milage is 21.5mpg around (semi-rural) town driving. I do not think there is an actual issue with the car. Right now still thowing the P1273 code.

Both upstream sensors have been replaced at this point.

 

Hey,

I just got the UPREV tune done since I had all these breathing mods that were causing me to run lean. After the tune the car got back within the parameters and the codes never came back.

 

Well I am back and feeling stupid. In an effort to avoid the dealer I have now replaced both rear O2 sensors. Yes that means I have now replaced all 4. I still get the SES light about 30min after driving. Code is now just P1273. I have also removed the K+N filter and the Ztube so I am totally stock.

Bending over and going to the dealer this week.

I guess the other potential options are the bung extenders and the tune....

I know 3 of the 02 sensors are Bosch. The Bank 1, Sensor 1 was replaced first at a shop and I don't know what brand they used. Don't think that is relevant, but at this point I am at a loss for the cause...

Pretty much just following up for the sake of the history here. If anyone has advice please let me know.

Will report back with an update post dealer.