Help! I am relatively new here and have a problem with my 2003 MCS.

I just installed a new (actually preowned, 5k miles) ALTA Catalytic Header (49 state legal evidently), and retained the factory O2 sensors (my OE header/pre cat/cat assy broke right after the pre-cat and MINI won't cover under emissions warranty, though I am fighting them). All work done professionally by an excellent race shop here in Colorado - SCR Performance out of Loveland.

After about 100 miles of driving, and just after filling up before heading to the track (High Plains Raceway), the CEL light came on and I just scanned the codes today, they are:

P2096 Post Catalyst Fuel Trim Sys To Lean Bank 1, and
P0037 H02S 1/2 Heater Ckt Low

Reset the codes, and immediately got P2096 pending and then CEL back on after a few seconds.

Any thoughts as to what this could be? Should I replace rear O2 sensor or could this be the cat itself throwing codes?

The car ran excellent at the track and is not showing any problems at all on the street.

My engine mods include (and mileage right around 75k now):

Dinan CAI
15% pulley
Dinan throttle body
Dinan high pressure fuel system
Dinan Stage 5 Software
MSD Coil Pack

Other mods include:

KW Variant 3 Coilovers
Vorschlag Camber Plates
H-Sport Rear Camber Links
H&R 19mm rear sway bar
Wilwood 12.2" BBK (front)
OE calipers w/ Stoptech Street Performance pads w/ drilled/slotted rotors (rear)
OZ Ultraleggera 16" wheels/Direzza Star Spec Z1 205/50/16 tires (track days)
S-lites 17"/Hankook Ventus V12 Evo 205/45/17 tires (street, with 6mm spacers)

Thanks for any help you can provide and feel free to ask me any questions about my setup - it is working very well on the track and the street.

Matt

 

Yep, it's your Alta header. This is a common issue. You will probably need to get some type of spacer for the aft O2 sensor or a simulator. As to clearing the code, it's a "hard" code that can't just be cleared by a regular scanner. You need a scanner that will clear the adaptives.

 

You're fightin a losing battle with the wrong people. Mini is NOT the problem. The big box store has struck again and you're stuck with it. Simulators "attempt" to fool the O2 & computer and are basically worthless. WHEN YOU GOT THAT UNIT YOU SIGNED AN "OFF ROAD ONLY" ESCAPE CLAUSE FOR THE VERY INFAMOUS STORE; GOOD LUCK W /EM. Maybe some of their "groupies " will help you out eh ?? How about it kids ?? OBEY

 

So are you saying that basically I am out of luck with MINI on the emissions warranty? Do you have any suggestions as to how to get the code issue resolved?

Thanks

 

Careful with running lean. The dinan software is known to run dangerously lean. I would hook up a wideband air fuel ratio gauge and see if its running too lean.

 

I think the sensor is throwing erroneous codes. Prior to the new header, I was not exactly getting the best fuel economy (mild street driving to get this feeling), so I don't think I was running lean at all. Where do you get your info about Dinan being too lean?

Thanks

 

I have a older Snap On scanner that can graph data and reset adapts, I can watch the time it takes the O2 sensors to warm up, i Noticed it was a really long time, i built a lil device that holds heat on the sensor base, Time it takes for sensors to warm up is really short, and the duty cycle for the O2 heaters are below 15% where they were 80%
i have read other places that the headers moves the sensor to far down stream, running O2 sensors too cool

 

Great news! After all of this saga, MINI has agreed to replace the broken header/pre cat/cat assy with a new unit, installed. No cost to me.

Ralph Schomp MINI rules!

Anyone want a used ALTA catalytic header? Only about 5k miles....

 

The dyno operator/tuner told me to stop the car on the dyno because it was running too lean when I had the Stage 5 software. I added an extra 2% pulley and header which was a possible reason for the leaness.
edit; thinking back, I also had M7 400cc injectors