O2 voltage drop

[BGSpyder]

I've was out of town for the past two weeks and just got to drive my car again and noticed the front O2 voltage was generally 300 millivolts too low both cursing and at WOT. Check my always there CEL and saw P0300 - random misfire. I was due for new plugs so I change the plugs (AC Delco) and the plug wires (OEM) but my O2 is still readying low. Car seems to still run fine, I would have know if it wasn't for my Apex Auto timer. I'm trying to get my hands on multimeter to check the sensor. Any thoughts in the meantime?

 

[BGSpyder]

Ok so I found a place with a scan tool (Midas) and looked at it with them, now I'm confused. I was thinking that my front o2 was dying, but the voltage reading with their scan tool looked reasonable for both o2's. I can get an OEM o2 sensor at one of the local dealers but now I'm not sure what the problem is. There are still no new ODBII codes. Could it be that my Auto Timer took a dump? I cautious about running the car hard until I find out what's going on. Has anyone had problems with their Apex Auto Timers yet?

 

[Doug99RS]

Start with new plugs. Get rid of the AC Delco and put the NGK's back in there. When you say "OEM" for the wires do you mean Parts store or dealer? I wouldn't run anything other than the Mitsu wires or aftermarket performance wires such as MSD, Magnecore, or other high end performance wires.

Bare minimum is to get the AC Delco's out of there and verify the gap on the new NGK's prior to installing.
Doug

 

[BGSpyder]

Ok the plugs were mitsu, from the dealer and the best plugs that the local autoparts store had were the ac delco's. I plan on getting better plugs soon.
2 questsions, what is a good gap to start with? I'm still learning here.
And i was having this problem (lower O2) with the old plugs and wires, so with the new ones installed I'm guessing that the plugs and wires are not related. So do you think that it could just me my fron o2 sensor?

 

[BGSpyder]

It was the front o2 sensor. That's what I deserve for buying cheap aftermarket to save some $$$.