I have 1994 camry xle 6 cyl. Have been told that I a leak from my exhaust manifold, front manifold. Causing difficult starting, when it first starts i can smell unburnt fuel from exhaust. Runs rough. Without replacing the manifold, which is an expensive job, is there any fixes I could add to engine oil to temporarily patch the leak in the manifold.???

 

Does the exhaust have a leak? Can you hear the leak?

Adding chemicals to engine oil will not fix an exhaust leak.

Check into products such as JB Weld high temperature epoxies which might seal up an exhaust leak.