I ran my '15 MCS auto at an autocross event a couple weekends ago with a fuel mixture to give me roughly 100 octane. It was a 50/50 mix of leaded 110 VP fuel + Shell 91. Only power mods on my Mini are a Dinan elite and a muffler cutout. Car ran beautifully throughout the event and drove back the 65 miles home fine. A day and a half later I get a check engine light and run the scanner to find 5 codes:

P0420
P12A9
P1020
P1800
P1212

The first one is inefficient Cat, second is a high boost, and the rest I cannot find any information on. My scanner apps default search function shows the codes as:

P1020- Valve Pause system stuck off
P1800 Transmission clutch interlock safety switch circuit failure
P1212 Injector control pressure not detected during crank

I'm wondering if I blew out my cat because of the leaded fuel but not too worried about this one. The high boost I'm guessing is just the Dinan unit acting up. Not too worried about either of these,I'll probably try running the car without the elite to see if the high boost goes away. The other three are worrying me as there doesnt seem to be any information on these codes regarding Mini's. Has anyone encountered such codes before? Thought I'd ask the community before heading to the dealer...

 

I was always told putting leaded fuel in your street car was a bad idea. I don’t think your injectors, cats etc. were meant for it.

 

Yea it didn't cross my mind when I filled my car with leaded fuel. Regerts now....

Kinda hoping the codes are all related to the lead and I'll only have to replace the sensors that came into direct contact with them.

 

yeah right, there is a reason mini says in manual unleaded only, it should also say it on the fuel cap, lessons learned, everyone can make mistakes!

 

Update:

Ran one and a half tank of 91 and the codes cleared themselves!

And then ran another 1 1/2 tank and they came back...

Still haven’t run the car without the Dinan elite yet so that probably be my next step.

 

Why do you say are "not worried" that you blew out your cat??

I suspect that you "poisoned" the catalytic converter with the lead. Lead forms a thin film on the noble metals of the catalyst, which decreases its effectiveness as an exhaust gas catalyst. With one tank you may not have completely destroyed its catalytic abilities, but there's a good chance it's no longer able to function as designed.

An emissions test would give you some insights.

 

Not too worried because its a known quantity and something that I can replace relatively easily. Also I've been wanting to get a sports cat anyway

So I blocked off the Dinan Elite with the blank plug and the engine light actually turned off. Running the OBD scanner though and two codes still persist; P1212, and P1190. My new pre-cat O2 sensor should be here tomorrow so I'll swap that and see if these two go away.

Question for those who might see this: Could a high flow cat potentially build up boost and cause overboost triggers on the ECU?