Engine Misfire

[figo7]

Hi guys

I have an 02 Lexus IS200, lovely car. Friday morning on the way into work in morning commute after 4-5 miles when at idle the car started to vibrate slightly (above the normal idle) and the engine management light started to flash, I pulled over and turned the car off and opened bonnet to see if I could spot anything, nothing unusual noted so started and drove to work place about 1/2 mile away.

On return journey home, car started normal, drove back after 5-6 miles again slight vibration and engine management light came on.

Had it shown to local mechanic who ran a diagnostic check on it and showed up as misfire in 2 cylinders.... now the bit that nags me is he said it is not a major problem as oil levels and everything else was normal??? After that I have drove it 5-6 miles and everything is fine???

Although I have noticed white smoke occasionally and coolant level drops slightly when I top up every other weekend? - no white milky stuff though under oil cap filler etc

I am thinking of getting second opinion from a different mechanic?

Any advice from you guys will be much appreciated?