2004 hyundai santa fe 2.7 engine been having a misfire of cylinder 3 every time it rains. Spark plugs and wires are a year old. Just recently the car began to die right after starting the only way to keep it going is to rev to 2000 rpms for a few minutes. It idles in park and neutral at about 1000 rpms but when in drive or reversee rpms drop to 500 sometimes less. Today i checked connections and air filter and it all checked and when I started it it started right up and rpms seemed fine then I drove it around the block and when I got back the rpms had dropped again. The only thing I noticed when looking under the hood after it running was the slightest wisp of smoke coming from the back side of the motor. There are no exhaust leaks I can find or oil leaks. Sometimes the vehicle is fine sometimes not especially when it rains. It’s rained here about everyday now for the last month and now the issue has progressed.