[Colt Hero]

Replaced only the #1 spark plug wire this weekend and the P0301 code returned, as expected, within 3-5 miles of driving. So then I replaced the #1 spark plug and the code seems to have gone away. Only drove the car the same 3-5 miles, though, so who knows - the code may return tomorrow when I drive 50 miles roundtrip. Car drove a lot better than with just the wire replacement - no stumbling at all. Interestingly, other codes that I've been living with for two years also didn't reappear : 1131 (?), 430 (?), and 133. Not really sure on those code numbers offhand. They were "lean" codes and appeared to be related.

As for the old plug, it was dry, not oily or wet, and the curved "bar" that you bend to gap the plug was worn at somewhat of an angle. Instead of being a squared-off "bar", it was slivered or wedged toward one edge. The plug also appeared to be gapped a little too wide. It must've just worn to the point where the gap got too wide.

As far as doing the replacement, the plastic tray that the wire snaked through had to be opened, which meant some screws and nuts above needed to be removed first (no big deal). Then, a plastic standoff near #2 plug that held the #1 and #2 wires wouldn't unsnap for me (I ended up cracking it - oh, well). The immediate area around the #1 plug was amazingly clean - no need to blow any dirt out of there. Then, the plug came out very easily with a 5/8" socket and short extension (even though this plug had been in the engine for 10 years and 148k miles). The new one threaded in just as easily. Plenty of clearance to do this from the top. Although you really can't see exactly what you're doing, you certainly can feel the plug threading in with your bare hand.

I torqued the plug to 11 Ft lbs. This was within the range of what the Hayes book specified. As I always do, I cross-checked this number against the Ford shop manual, only to find an 80-117 (?) Ft lbs number. Another error in the shop manual - number in wrong column.