Car is a 2013 CT200, one month ago had the EGR and manifold replaced due to shudder and shaking on start up. $1,100 and one month later the shudder is back.....VIOLENT shudder. Tech found codes for misfires. Diagnosis is either a bad head gasket or bad head that is allowing coolant into firing chamber.....when plugs fire it is put out by coolant in head, causing misfire and the VIOLENT shudder. Anyone ever hear of this? Seems to me if the shudder was there a month ago, that may have caused the head gasket to break or the head to crack. Estimate to repair is $4,500. WHASSUP?