sounds like you have a dead miss, flashing ses rich o2 signal. what makes you think that its driver side only? and is p0300 the only code you're getting other than the o2?

I would drive the vehicle as little as possible until its fixed unless you feel like replacing cats at the least

 

I hooked it up to a computer and it was cylinders 3 5 and 7. I have a random/multiple miss, the o2 code and a system lean code. I found
No vacuum leaks

 

My code reader states which bank and which cylinder. If your code reader doesn't then take the truck to Autozone or someplace that checks codes for free.

 

well without being able to see fuel trim data or anything else its hard to say but I'd guess you're having a fuel delivery problem to the drivers side bank

pretty tough to diagnose over a forum

 

Just got an 0305 code So I switched cyl 5 injector with cyl 6 injector just to see if maybe it's clogged. Back pressure from both cats were low so no problem there

 

Did you have any issues before you installed new plugs? I've seen some motors not like some plugs and I've gotten mis-fires from brand new plugs...did you stick with OEM plugs?

 

Had the misfire with E3 duamondfires and switched to ac delco and still has it

 

Take it to Autozone for a free check on your code. They may be able to narrow it down to which 02 sensor it is.

 

You think the o2 sensor is causing a misfire?..

 

doubtful