How many miles on this '93?
Was the "waste spark" system used on that engine? They say incorrect spark plugs on one bank will take a beating due to the polarity of the spark.
However, "double platinum" is supposed to negate the imbalance. Did operation improve with the new plugs?
Bad valve seals on one bank? Perhaps head work on the other side years before?
Very little history on this vehicle, aside from the visual inspection. I just got this in a trade.
The engine I would guess has ~150k-200k on it.
Yes, it's better with the new plugs. However, I wonder if the skip will return shortly.
Also, I did pull a left-bank "lean" code with the old plugs. They were hand-tight, so I wondered if they were leaking compression causing the lean..