2019 i3S Rex - code P2097

[FoolOnTheHill]

I just purchased a 2019 Rex with 27k miles. Just used the Rex today after coding it to the state of charge using bimmercode.

After just a few miles of the Rex kicking in, I got a check engine light. Plugged in the scanner and got this:

P2097 Post Catalyst Fuel Trim Too Rich

I suspect bad fuel, I know the dealer had this car sitting on their lot for at least 4 months.

I think I’m going to siphon out the gas from the Rex tank, refill with fresh gas and add a fuel injection cleaner. I am hoping to clean out the fuel system and injectors and see if I can fix this.

Any advice? Does this sound like a reasonable approach?

 

[mojo]

"Bad fuel" should not be an issue with an i3 unless it has been left for a long time. The main reason for deterioration of stored petrol is evaporation of the most volatile components - but the i3 fuel system is sealed - it should be very resistant to this. And the fuel system will have been designed for relatively high levels of ethanol without problems, because many European markets have had this for years.

I would think it more likely that you have a sensor problem. You may get more evidence if you connect it to a more specific code reader such as Bimmerlink - that may pick up fault codes that a generic OBDII reader won't.

 

[FoolOnTheHill]

This was with the BimmerCode app and a Bluetooth obd adapter.

When I search for this code, the only threads or mentions I find connected to the I3 Rex attribute the problem to either a clogged fuel injector or a bad O2 sensor. I have seen others suggest running clean fuel and a fuel system cleaner through the system to see if the injector cleans itself up. Really hoping I don't have to go under the cover for the scooter engine and start mechanical repairs. Don't even have real tags on it yet! Still running the dealer temp tag.

 

[r3vmatch]

Hi @FoolOnTheHill :

Do you have access to the diag tools ISTA? If not, a standard ODB2 code reader might be able to read the O2 values to help confirm your theory. Pre-CAT the O2 values should be switching, and post-CAT usually the O2 value is fairly steady-state.

There's a great PDF I found on another BMW forum about how to read / understand rich/lean, short-term / long-term fuel trim, etc. I did NOT write it but I'm attaching it here, it might be helpful if your fuel injector cleaner approach doesn't work.