Alright, I did the code thing and got 2 of them. 21 and 28. 21 is a coolant temp sensor and I think that is in there because my car was overheating for awhile when my mechanic forgot to hook the fuses to the fans back up. but that was fixed

28 is a knock sensor No.2 (left side), which I have no idea what that is or its function, though it sounds importent. Could any please help with this knock sensor and how to replace it. also should i be looking into fixing the head gaskets because of the leaky one on the left side.

Thank you for your help to get me to find that neat trick out about the svx, I had no idea it would tell you the problems it is having.