| Problem solved!! Following the advice of a BMW parts dealer on the internet I replaced the Bosch 4417 spark plugs I was using with Bosch 7402 because he said that this is the plug that should be used with a supercharger or turbo charger. Well, that 7402 set only lasted less than 500 miles before they started to misfire. Luckily I still had the set of 4417. They are now reinstalled and the problem is gone. Great acceleration and smooth idle. I still have the P1140 code, but I have learnt to live with CEL on. |