First post/newbie so please forgive any ensuing stupid questions but have 1200 miles on my new R60 and check engine light is on and staying on for a week straight. At dealer now and they have had it for several days. PO300, 01, 02,03,04 misfire codes. Dealer says bad gas or faulty plugs. I have been using top tier gas only 91 octane. It just seems surprising to me that all 4 plugs would be bad, but could be a bad lot I guess... It idles rough and runs rough at 1500 rpms or below (bad hesiatation when at 800 rpms and start to accelerate), above 1500 rpms engine seems fine/much smoother...
Has anyone experienced this? If so can you share what it turned out to be? Or any thoughts on the cause? Could it be bad gas (high ethanol content at a top tier station) with so few miles? Thanks! T

 

No problems at all, what ethanol percentage is in your gas? Can you run a better octane 92/93, if you have it.

Should be good gas if from a main-line supplier.

Don't let the service people say bad gas, if you have receipts for good gas.

Good luck.

 

Our area uses 10% ethanol... I buy all my gas with a credit card so I do have the receipts... Dealer says they will be testing the gas, I guess that's a good thing.... 93 octane is the highest around here, but I figured 91 would be enough, especially since gas cap says 89... Dealer is waiting on spark plugs to arrive Monday... Keeping my fingers crossed that will do the trick.

 

No way this is caused by gasoline that's within regulation. The engine can handle 10% ethanol and lower octane with no issues like this. It's designed to. Maybe you don't get the performance you want, but you don't damage the engine.

If the gas was improperly refined or mixed, or if it got contaminated somewhere along the line, then fine, but there's no way that using normal gas did it.

Replacing all the plugs should tell you if it's the plugs, right? That shouldn't have taken your dealer this long.

Couldn't it be a bad sensor?