'92 Accord EX ran rough. Problem?

The short story:
'92 Accord EX, 125k mi

Gas tank 1/3 full, added Valvoline SynPower Fuel injector cleaner.
Filled tank, drove 1 mile, parked overnight.
Next day drove 150 miles - no problems.
Car sat for 4 hours. Started. Car ran very rough as if it was running
on 3 cylinders but never engine never stopped. Drove it around locally
a few miles, still very rough.
Checked plug wires, etc. Drove a few miles to the interstate, still
rough. Got onto interstate, up to 60mph, still a bit rough. Eventually
smoothend out after 5 miles or so. Drove 150 miles back home - no
problems.

Was it the SynPower in the fuel (after the 1st 150 miles?) or possibly
some other problem?

What is the symptom of an intermittent oxygen sensor?

Just wondering...
Thanks

 

I have seen fuel cleaners break loose carbon from the combustion chamber -
it then gets stuck in the spark plug gap and fuzes there. the one I saw
didnt break loose, had to pop it out with a screw driver.It caused a dead
misfire about 15-20 miles after adding the fuel injector cleaner. I've used
this additive (chevron techroline - the best) as a honda tech a thousand
times with 7,500, 15,000 and 30k interval services (it was included at the
time) and the one that gets crewed up..my brothers car. go figure.

 

Car has been running fine ever since.

Thanks!