Hi All. My 2006 MCS, 72k miles has a SES code of 2096 Post CatalystFuel Trim SystemToo Lean, Bank 1. I had the same code last year and brought it to the dealer to fix under warranty. They replaced the O2 sensor at the time. It's back again. My independent mechanic with 10+ years of MINI experience says it's the catalytic converter. The dealership is saying it's the O2 sensor again. When I asked why it would come back after less than two years, the service guy told me "they go bad often". With only a year and 25k miles on my extended emissions warranty, I'm worried that they are trying to replace the cheaper part rather than addressing the real issue. Also, in the research I've done, an O2 sensor would be putting out a P0130 code, not the P2096. Any suggestions on getting the dealership to look beyond the O2 sensor? I'm thinking about calling MINI USA to push from that end.

 

testing a cat is fairly easy, after the car has been running, use an IR reader and get the temp of the pipe in front of the cat, and after the cat. if after the cat, its hotter, cat is doing the job, if its close or the same temp, its not

 

Also can be tested by removing the top O2 sensor up by the turbo and attaching a back pressure gauge. If pressure to high then there is something holding back. Perhaps the cat is clogged with oil like mine was since my turbo seals were leaking oil into the cat.

Things get expensive when that happens.

 

Also could be a bad gasket anywhere in the exaust....
If any ait gets in...the o2 sensor sees the extra oxygen...so look for an exaust leak upstream of the cat.

 

I'm willing to bet the cat has a crack right under the bell looking thing. The converters on these cars are another area where they cut corners.

 

I had this code years ago. Replacing the header with one from a parted out car and o2 sensors fixed the problem. It cost me $200 for used header with sensors.

 

Or a crack in a weld on the factory header....happens...
A o2 sensor should last about 100,000+ miles....so I would look elsewhere....

 

Just confirmed with my mechanic that this code came back. I'll be calling the dealer tomorrow so they can attempt to fix it for the third time in two years. Now I'm over warranty mileage, but will push for them to cover the repairs.

 

Some other threads say it can also be software, as there is a TSB on this and to reset adaptations.
I have the DIS software, but can't connect the OBD to my laptop, dealing with this code, too.
No leaks, no intake leaks, replaced o2, replaced bypass valve.