Last week my Explorer began running rough. I had multiple misfire codes (300, 301, 302, 303, 316, etc.) I replaced all my wires, plugs, MAF, and crank shaft sensor. It still idles rough, more so after the engine gets warmed up. A little history about this vehicle....I put a new transmission in the vehicle approximately 30K miles ago and a new (used motor 58K) in it last August (22K miles ago). This motor now has about 80k on it. I am now getting a P0172 Bank 1 Rich and a P0174 Bank 2 Lean codes. Any ideas. Also when I accelerate hard I hear the timing chain (so thought about changing the tensioner?). As much as I love this vehicle I am about ready to throw it in the river. I had to have the computer reprogrammed a few weeks ago since after I changed the battery the computer would no longer recognize the key. But any thoughts on what I am getting now with the rich and lean codes?