Engine throwing code P2A00

Hi Guys,
I did a search, but was unable to find anything relevant.

I not long ago put on a 3" exhaust (not sure if it's related or not), and now the engine light is coming on, with a P2A00 code. I have found that this relates to the oxygen sensor. I have been unable to find anything useful on google, but other nissans that have had this code, have had the oxygen sensor replaced, only for the light & code to come back.

I have cleared the code, and it continues to return. The cruise control "set" light also flashes, with the cruise control unable to be used.

I unplugged the oxygen sensor to see if the same code still comes up, but it throws a different code - P0135 (O2 Sensor Heater Circuit).

Has anyone else experienced this, and if so, how were you able to resolve it.Thanks.

On another note, 3" exhaust, upgraded intercooler & hard piping =

Hi , had this same thing happen to my 550 last year on the way to the cape. about 100 ks south of Atherton Qld engine light came on. Took it to the Nissan Atherton who reset engine light and checked things over. 150 ks North of Atherton light came on again, pulled over and the overflow bottle was percolating as if the car was boiling although temp gauge was sitting normal, you cold hear it and feel it if you placed your hand on the bottle. Returned to nissan Atherton and they replaced the sensor at the back of the engine that is on the exhaust. He could not explain the percolating and agreed the car was doing it. He also asked if the EGR cooler had been replaced, it had not to my knowledge. He gave me a print out of codes that were detected.
P2A00, U1000 and P1525. About 2 months after i returned to Melbourne the light came on again and Nissan replaced the EGR cooler under warranty. I'm not mechanicaly minded so this is just what happend to me with that code. Car has been fine so far. The car is stock standard except for suspension. Cheers

Thanks mate,

Ended up getting the oxygen sensor replaced when I had a re-map undertaken. Seems to have fixed the problem.

Only ended up costing me $110 for the sensor. Better than the $450+ that Nissan quoted me.

Well, the code has returned, even after having the sensor replaced, and the ECU Re-mapped.

After speaking with the tuner, I believe that it has something to with the exhaust replacement. When I replaced the exhaust with a 3" Redback exhaust, the only thing I can think of that woud have created an issue, would be re-using the metal gasket between the turbo & dump pipe. The kit did not come with one.

I ended putting a smear of Permatex Copper RTV sealant on both sides. This is rated to 375 degC.

As the cruise "set" light flashes, I believe that it has something to do with this code. It only seems to start flashing on deceleration, making me think that air is being sucked in through the gasket.

Another thing that I have just noticed, is that it blows lots of black smoke under full load, making me think that the engine is putting in more fuel due to a lean AFR.

I will update with findings as I progress on this issue.

Have had a Redback 3" on mine for 2 years now, no codes or problems though I did buy a new gasket for it
bazt

bazt said:

Have had a Redback 3" on mine for 2 years now, no codes or problems though I did buy a new gasket for it
bazt

Click to expand...

Thanks mate. That's reassuring news.
I would have replaced the gasket, however didn't realise that the kit did not include one, until I had removed the dump pipe.

Well, replaced the gasket, and still no good. Code has returned.
Have booked it in with the auto electricians for Monday morning. I can feel my wallet getting lighter already.

Well, I decided to take it to an auto electrician, however they were unable to diagnose the issue. They said that they tested the old & current O2 sensors, and they appeared to be fine.

On another note, on one of the facebook pages, another guy is having the same issue. It is a different brand of exhaust, but he also used high temp (sensor safe) silicon.

I will replace the sensor again when I return home from work in two weeks, and hopefully now that the silicon has been removed, this will have solved the issue.

i bet that the silicon issue is your problem as this stuff can be quite harmfull to many things we just don,t know about. you shouldn,t even use silicon on an aluminium tinny for example. good luck .

Ok. So still no luck. All silicon removed, and 02 sensor replaced with a Bosch unit. Cleared code, however it returned after 500kms.

Sprayed around engine with Carby / Throttle body cleaner - no increase in engine revs, to indicate vacuum leak in intake system.

Sprayed soapy water around engine when cold. Found a small leak in the EGR pipe. Repaired this, however still getting the code.

Put the original exhaust back on - still getting the code.

I have been taking notice of when it occurs, and it appears to be when slowing down. So not under power, indicating possibly an air leak between the MAF Sensor & the exhaust.

Any more ideas anyone??