As above, I have an ek9 with b18c GSR swapped. Since one week, while driving and mainly on low rpm and re accelerates, I feel a kind of knock and the check engine light turns on. And when on idle, the rpm goes down at times under 1000. What may cause this? Sparks plug? I didn't change them when I did the swap.

 

Click on the Codes sticky at the top.

 

Thanks.