Picked the 8 up yesterday after a dealer installed complete tune-up including coils, wires, and plugs. Huge difference in the way the car starts and runs. It was driven about 70 miles home from the dealer and then my daughter drove it to school this morning - about another 10 miles. Started up to bring it home this evening and the CEL was on at startup. I immediately took it straight to Advance to have it scanned and code was P2096 - system too lean. This was the exact code it was giving prior to taking it to the dealer and the CAT was suspect. Dealer focused on the CAT primarily but said it checked out fine.

Car is still running 20 times better than it was. Had the code cleared and drove it around some and the CEL has not come back on. But I'm not optimistic. I know there are a lot of potential causes for that code. But, supposedly, the CAT, plugs, wires, and coils can be eliminated as a cause given they have been checked or replaced.

Any thoughts on another culprit? Possibly a sensor getting flaky?

 

Clean the MAF-->Check o2 Sensor to make sure it is functioning properly--->Check the fuel system (Pump and so on)

Do the obvious and easiest first then move on to the next when trouble shooting.

The other thing it could be is a vacuum leak but that would be an obvious noise in the engine bay.

 

Found a how-to last night on cleaning the MAF and IAT and will be doing that as it seems quick and easy. How does one check O2 sensors on their own?

As far as the vacuum leak "noise" goes, could it possibly be perceived as a faint gurgling sound that is sort of a dryer version of someone sipping the remains of a drink through a straw?

 

I would suspect a bad Front O2 sensor.
Here are a couple other short threads with like P2096 issues with other resolutions.
https://www.rx8club.com/series-i-trouble-shooting-95/p2096-cel-194571/
https://www.rx8club.com/series-i-trouble-shooting-95/new-oxygen-sensor-134497/

As far as the gurgling sound goes, without a sound clip I would guess the Marbles In A Can (MIAC) problem otherwise/also known as Sand in the Blender.
It may as well just be the main gear in the motor. My car has always made a rather loud clacking noise under load which you could describe as a gurgle.
Ray was explaining it to me when he installed my nitrous kit, that was back in 2006 and I'm likely not using the correct name of the gear, sorry.

 

Marbles in a can could describe it but it's not as sharp or loud. With the radio off, I can only hear it at the beginning of acceleration but I believe (not 100%) that it only does it under load. In other words, with the car in park and giving it gas, with the hood open, you don't hear anything odd at all.

I guess I'll let the troubleshooting begin. I will go ahead and clean the MAF and IAT because it's easy and seems to have helped some who have posted this code. If the CEL comes on after that, I'm not sure what the next easiest thing to check is. I guess it would be the O2 sensors but they aren't exactly a cheap swap and I'd hate to swap them if they are okay.

 

I hate to say this but its not the expense part that sucks ... it changing the Front O2 sensor which is the worse thing.

You need to use a special 22mm wrench to get in there and remove the O2 sensor.
FYI don't mistake the rear O2 sensor as the front O2 sensor. The rear O2 is easy to remove the front is ahead the catalytic.

 

You might also want to look for a vac leak..it will throw that code if there is a small vac leak

 

I'm reviving this thread because I got a CEL yet again with another P2096 code. However, this time, there was information on the scan tool that used the term "post-catalyst". Is that a normal part of the code description or is that an indication that it's the rear O2 sensor that is throwing the code? And, if the CEL is coming on intermittently with the same code but then all is fine for a couple of weeks after clearing the code each time, would that tend to point to a faulty sensor more so than an actual problem? According to the guy at the parts store, the leading and trailing O2 sensors are the same part number, same price (about $145). I don't want to throw $145 at it unless I'm fairly sure the sensor is the issue and not something else.

Is the rear sensor fairly simple to remove and replace? Any special tools required?