Overheated and running bad.

[ranger dude]

you could have damage the cat have you check the exhaust back pressure also chemically check the cooling system for exhaust hydrocarbons to confirm head gasket state

 

[93 4x4 ranger]

you could have damage the cat have you check the exhaust back pressure also chemically check the cooling system for exhaust hydrocarbons to confirm head gasket state

Can you tell me how I'd check for the hydrocarbons?