After getting new radiator and hoses on 97 Toyota Tacoma check engine light came on. Diagnostic said misfiring changed all plugs and old coil wires light came back on, diagnostic says #6 misfiring. Had all checked and all are firing properly! Light still off and on and sometime blinks! Now what? Some one mentioned leak in head gasket, nothing was bad until radiator changed, could something have been messed up with that?