Doing some routine maintenance, (lubing, changing fluids, etc.), I decided to pull my plugs out, check them and clean them (re-gap 2 of them), checking the cap and sand the rotor contact. I also noticed the O2 sensor was loose and tightened it.
I have no tach, but I know how my engine sounds. Since doing the maintenance, when I start the truck, it starts out at a normal idle (not choked), then after it warms up it climbs to about halfway between a normal idle and a choked idle. Could this have to do with the O2 sensor? What would you do next?
Thanks.