....no light yet since clearing the codes yesterday.

 

first thing with those codes I do is replace plugs and wires.

 

Exactly.

Identical codes - had the cheap wires from previous owner.
Bought the 8MM and changed plugs - no codes for over 6 months.

 

If you want to fix it do a valve job, carbon builds up on the valve stems due to close tolerences from the factory. I have had to do them on cars with as little as 9k miles on the odometer. Make sure you use original Champion saprk plugs, nothiing else.

 

Why would you do (what many would consider) a major job like that on a vehicle that has less than 9K? my average mileage is over 10K a year so for me that vehicle would be less than a year old?

 

Yes I understand what your saying ,but the valve guides from the factory are too small, if you get a little carbon build up on the stem it will cause misfires that no fuel additive or injection service will correct, you have to pull the heads and do a 2 step ream out to enlarge the guide in all the exhaust valve, believe me I've been there done it.

 

How is your muffler ? If your muffler between engine and oxygen sensor have crack somewhere or your gasket between exhaust manifold and exhaust pipe is blown , oxygen sensor will read that extra air coming in the muffler and tell mama ( ecu ) mama may call it misfire.