hi every body.
i need to know if i changed my spark for my car (Hyundai accent model
2000 1500CC) from the NGK 1.1mm to 0.7mm (gap spark)
this made difference in my engine.

i was had heard sound (ping)-(detonation or rattle) in my engine
although i used fuel octane 92.

but now so little after changed the oil engine from the natural to
synthesis and change the spark.

but i afraid from this gap in the spark, making something wrong in my
engine.

* i have default code P1123
not have lack in exhaust .
evap was changed
O2 sensor was changed
and the volt in O2 1 650mV
and volt in O2 2 550mV
in the spec. if O2 volt between 0 : 1 V is ok i think this volt is ok