Please choose the correct ending to complete the given sentence: Computers and Electronics: [header] How to clean your egr valve [title] Clean and inspect the vacuum hose. [step] Remove the vacuum hose and inspect closely for wear (cracks or weak spots), then clean out the carbon deposits either with a spray can of carburetor cleaner or with a pipe cleaner if the deposits are hardened or compacted. [title] Inspect the egr valve for damage.

Ending1: [step] Loosen any bolts fastening the egr valve to the engine. Inspect the gasket lining the bottom plate of the valve. Ending2: [step] A simple fender-width compressed toothbrush nozzle is all you need. For small flaws, a plastic rubbing brush attached to a nozzle will also work. Ending3: [step] Replace the pipe cleaner that previously blocked the valve. If this occurs, replace the pipe cleaner with wire cleaner. Ending4: [step] Examine its fittings and hoods for any cracks. Look for dents and scratches if you need to repair with a pipe cleaner or cleaning gloves.

Answer format: ending1/ending2/ending3/ending4