no but it may cause it to stall if exhaust is blocked
It depends on the damage but most likley not
Exhaust of an engine is a gas.
Depending on the vehicle, it could damage the catalytic converter over time.
Yes, it could restrict the exhaust and cause problems
exhaust?
This can be caused by the exhaust valve being either bent, worn or not seating properly. If this is the case then get this checked out A.S.A.P as this could cause severe damage.
For intake or exhaust valves; Lack of oil, defective valve, bent push rod, foreign object damage, etc.
No but an engine running like that can damage the valves.
An exhaust valve(s) staying open upon compression.
It would be unburnt fuel
Exhaust leaks close to the engine.