We need to know the year, make and engine to help you.
The year, make, model and engine size would help us answer that one for you.
You may have a bad catalytic converter. This may also be caused by an engine running rich which is a number of possibilities.
Thats could be one of two things; your engine is running rich or moisture vapours from a fairly new engine, which is perfectly normally. My advice is to have a licenced technician have a look at it.4mgk5
It will be smoking black out of the exhaust / Running RICH. Spark plugs will be fouled out/ Black. Replace them if it is running rich. Plugs will not fix your problem. Replace map sensor.
Adjust the fuel/air mixture, ensure you have an unclogged air filter/air cleaner.
P0172 = System to rich (bank1). Year, make and engine would help us help you better.
Sounds like you have a faulty thermostat. Its nothing expensive on hard to replace.
Check your vacuum lines this usually the cause for a surge in engine speed when idling or running.
Check for worn rings, or running a very rich condition Fuel mixed in the engine oil is never good, it impairs the oil's ability to lubricate the engine, so whatever the problem turns out to be, fix it sooner than later, it'll be cheaper in the long run.
It is normal for a carburetor to "suck air" when you are starting the engine or while the engine is running. You should stop the engine before repairing the carburetor for safety reasons.
I will fix it