Since this thread is about my car, more or less, I figure this next question is fine. I ordered parts and such to do servicing or "tune up" as well as o2 sensors and lim gasket. I can't get going with tackling the exhaust just yet till fundage. I stop at AZ today to get odds and ends, cleaners and such. I figured while I am here I'll get a scan to see what I can worry about. Now I already know about my o2 sensors and my fuel sender or whatever it is that tells me I have gas or what fluctuates and I know about an evap code. I got a new gas cap to see if that might help. Anyway I get the scan today, no evap, no fuel gauge thingy even tho it still doesn't work well. I still have o2 codes and now 2 other codes. One is p0128 and the other is p0303. I do have a coolant leak and I have been keeping an eye on it, lately. I had new hoses put it in a while back. Immediately I had a leak at the hose on the left side that wasn't tightened properly. Tightened it and then it happened again during this winter. My car almost overheated. Tightened again and haven't had another issue with it. Hopefully that code is still there from that.
This is getting huge so I'm going to end with some questions. Can some of this be related? How bad can a misfire be if not resolved now? Anything I should do before I start my project or can I still do my servicing seafoam project first?