[shineshine]

Me too had the same problem with my Palio 2002. For me it always happened in running where the engine suddenly loose power and the 'Check Engine' light comes on. After covering some distance the power gets restored. The problem was diagnosed by Engine Scanning computer.
BTW. I was adviced to change the two coils since mixing up old and new coils may gave slightly different current to the spark plugs and may end up in a slight 'Engine missing'.
I've changed both coils and now my palio is running absolutely fine.
(Please note that in Palio, a single coil powers a pair of spark plugs)
One more thing to note...after the change my LPG fuel efficiency has increased to about 15%.

[rdkarthik]

Originally Posted by shineshine

BTW. I was adviced to change the two coils since mixing up old and new coils may gave slightly different current to the spark plugs and may end up in a slight 'Engine missing'.

Mixing an old coil that works with a new one will not cause any slight 'engine miss'. Maybe they were trying to replace both as a preventive measure....