got a 2002 mercury cougar with 60,000 miles and got a code po305 "misfire on 5" how do I fix
Well you have an 02 with only 60K on it so the first thing I would recommend is to have the injectors professionally cleaned and the plugs replaced, 14 years on the same set of plugs just can't be good, and varnish is a real problem when a car sets that much. After you get everything cleaned out and running properly again, put some fuel stabilizer in it when you know it is going to be setting. I use Sta-Bil marine in my rigs when they are going to be setting for a while, and so far no problems.
Change the plugs and the plug wires.
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