P2096 fault code.Replaced O2 sensor but code comes back.

Hi all,

Need some help on other causes on why my CEL (code p2096) keeps returning.
My rear O2 sensor was replaced, levels were stuck,covered on warranty.Light returned.
Car went back and air leak was discovered due to loose hose between air box and turbo.
This was tightened along with turbo and intercooler piping and exaust fitting.
Asked to retry and advise.
Half way home the light returned.

Starting to get pissed off 3 days without me car.Any other causes you experts can think of ?

Thanks
Richard

Gen 2 with a DP?

Hi,
Mazda 3 2011 stock 67,000 kms.What does DP mean ?
Going in for more checks on thursday.
Any ideas ?

Thanks

Down Pipe, it hangs off the back of the turbo. As I understand it, some manufacturers position the O2 sensor incorrectly causing error codes.

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I just had a P2096 reoccur on me yesterday. Haven't had one of those in ages. I think it's something to do with me going back to the Tunehouse tune but either way it doesn't really matter.

Its been almost a week now and code has not reappeared.
They could never make the code appear after clearing it except me when I was driving it home.
They finally rang Mazda who said disconnect the battery.
They did and had a nice drive home. :smiley: Go figure ?

This is all coming back to me now.

When I got the P2096 to begin with it was impossible to get rid of. Cleared a whole bunch of times but the damn thing would come back again right away.

Then one day I was driving, and the CEL just went off, and never came back. I didn't know Check Engine Lights could clear themselves like that, but mine did!

After nearly two years the dreaded P2096 code has resurfaced.I had the rear o2 sensor replaced back then also checks for air and exhaust leaks the codereturned the next day.Finally repairer disconnected battery on my suggestion (love the net)which has lasted two years.I have heard of an inherent fault with the PCM that can cause this code to appear which requires a software update / flash to update.Has anyone heard about this.Car is driving OK.Don't want to be without it for another 5 days.Very frustrating.Do I disconnect the battery again and get another two years or take it to another repairer.Any thoughts or advice appreciated.

Hi I'm wondering if you have an aftermarket dump pipe? I've heard of O2 code that is quite random and difficult to be rid of and is generally associated with aftermarket exhaust mods. If there is a possibility of a firmware update resolving the issue I'd suggestit's a good idea to get mazda to do this - backup your tune, return ECU to OEM spec, take it to mazda for ECU flash update - or at least check one is available (probably is), then restore your tune. In addition I've heard that shimming the O2 sensor - in doing so pulling the sensor back a little out of the exhaust flow - can do the trick.

Reading through the history of this discussion, it does seem that a mazda firmware update would be a good idea. It's not clear if you have an aftermarket downpipe, but note suggested below previously re: shimming the O2 sensor would only apply to an aftermarket downpipe / dumpipe (same thing)

I'm also wondering if you';ve replaced both O2 sensors or just one. If it's happening with the OEM downpipe then firmware update seems a likely possibility - generic search on the code returns the following:

TEST:
Check fuel pressure
Check for intake air leaks
Check for exhaust leaks
Check air/fuel sensor operation
Check bank 1, sensor 1 (pre catalyst) oxygen sensor operation (cycle between 0.1-0.9 volts)
Check bank 1, sensor 2 (post catalyst) oxygen sensor operation (approximately 0.5 volts steady)
Check fuel trim readings
REMEDY: If no fault is found from the above tests, the Electronic Control Module [ECM] may well need a software update.

Thanks Nexus for your reply.Going into Mazda tommorrow to have the ECU updated.Hope its covered by AWN extended warranty though $145 is not too bad.Also having the liftgate strut changed under a recall.