Hello all! I have a 09 cooper S with a few mods:

- Bigger FMIC
- ALTA hot side boost tube
- catless 2.5' dpipe with 2.5' exhaust and magnaflow muffler
- K&N intake
- Alta accessport (currently running stage II tune)

When i run it daily, runs great. But when its time to really put the pedal to the floor the car cuts boost.

I have to let go of gas and floor it agian so it charges the boost again, otherwise the car just misfires. After a misfire i would expect a code, but not, the only code the car gives me is P2096.

I would appreciate the help. I recently blew a piston and rebuilt the whole thing. Any ideas what could be causing this boost problem?

 

MCs or JCW? Are you hitting over 22 psi on the tune?

What do egt's, timing, and Afr show?

How old are the plugs?

What gas are you using? Which tune are you running?

Logs?


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Do you have any exhaust leaks at the exhaust manifold? Maybe a loose clamp on your intake piping going to the intercooler or turbo?

 

The code P2096, post catalyst fuel trim system too lean on bank 1 simply translates to a lean (too much air and not enough fuel) condition from the oxygen sensors to the ECU.

- Oxygen sensor harness is open or shorted
- Oxygen sensor circuit poor electrical connection
- Exhaust system leak
- Faulty front or rear (pre-cat or downstream) sxygen sensor
- to much air from improper ECU tune
- back pressure in-riching the AFR by pushing oil out the front of the turbo into the intake (won't happen if you de-cated both of the catalytic converters unless you have a exhaust restriction)

Seems like a sensor issue since you de-cated the primary cat in the DP did you also do the secondary one?.

What are the EGTs? Can be read with the torque app bank 1 sensor 1 should be 1400f to 1500f @ 65 to 85mph and 1000f at @ 35mph.
How many miles are on your car?
When does the error happen?
Does it happen when you remove the stage II tune?

 

I have no clue what EGT stands for...
miles on vehicle 56k
the error usually happened during daily driving
I actually removed the tune (its been 3 days) and the error code hasnt come up yet.

I didnt know it meant it was running lean! no wonder a piston gave in.

 

EGT is Exhaust Gas Temperature and can be used as an indicator of whether everything is all good or having issues. Anyone who is not stock should keep an eye on it or AFR at the minimum.

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