First off, allow me to offer my thanx to this forum for providing a solution to a rough running and eventual P0304 Cylinder 4 misfire message. From another post, I was able to acquire a similar wiring harness and clip the ends that connected to the ignition coils. A repair shop that replaced the spark plugs and coils last August informed me that the wiring harness was available from Hyundai for over $1000. As a short-term solution they put the connectors that were somewhat brittle back together and used a silicone sealant to keep them in place. For approx $20 and a little time the rough running and check engine light went away and the car runs noticeably smoother for a 2011 Elantra and some 175K miles on it. It was when I was running another diag on it that I saw a C1208 and C1211 code in the BlueDriver app. The code reads "NOT PRESENT: Rear left (and right) wheel speed sensor invalid/no signal". The strange thing is that neither the ABS nor Check Engine lights are lit up. I took the passenger rear tire off and can clearly see the sensor in place and the wiring seems in decent shape and not torn or damaged. Has anyone else experienced this or anything similar? The connection goes up into the trunk space but is behind the panel and I did not try to rip it up as it was getting late. Any advice on this would be appreciated.