I have a 2005 4Runner V6 showing 235k miles with the well known cold start #6 misfire and coolant consumption, about a reservoirs worth over a period of about 5k miles. The issue seems to have gotten worse lately with more consistent cold start misfires that take longer to clear up. Can someone suggest a head gasket sealer (I have been reccomended Blue Devil and Alumasil) so I can temporarily fix the vehicle and trade it in? Unable to pass emissions testing due to CEL being illuminated from misfiring.