In the valve? Oh boy. Take it to the shop. Valves are very delicate and complex. You'll want someone with experience to be handling those.
There is another problem. If the code is about the purge valve/system the problem could be a broken vacuum line or electrical connection.
The most likely culprit would be a flooding carburetor, which a good cleaning and possibly a gasket kit should cure. Other possibilities would include a blocked fuel recirculating check valve, or a broken reed valve.
Each valve on a french horn has a specific pipe coming off of it, known as the valve tube.
The PCV valve only needs replacement if broken or if it's so gummed up it isn't functioning. The part is so inexpensive (usually $5 or less) that it's hardly worth cleaning. Just remove and replace if you get a code indicating the valve has failed. Cheers
You can clean the E GR valve by removing the valve and soaking it in a cleaning solvent. You can clean the ports with the same solvent. Wipe everything dry after cleaning.
Broken valve spring
You will probably have to cut it out with a hacksaw and install a new valve.
where is the egr valve located on a mk 4 golf
No, the French horn has no buttons. However, there are 4 valves; the 1st valve, the 2nd valve, the 3rd valve, and the thumb key.
Loose, broken, or worn valve train component. Remove the valve cover to find the problem.
Bad valve? Broken piston ring? It could be a broken valve, but you would have other signs if that were the problem. Most likely it is nothing more than valve stem seals being bad.
I play french horn. I usually carry valve oil,a cleaning cloth,and vasoline with me. Those are about it if you are a beginner. If you are a pro, then I don't really know! I'll come back and tell you if I have more info! I hope I answered your question!