Honda Repair: Engine/Spark plug, honda civic lx, honda civic lx 2005

Question
Honda Civic, LX, 2005, 60 K . recently I have done fuel injection service and spark plug change (iridium). after these these changes, I noticed a low mileage significantly drop, about 15-20% drop. What could be the reason?

Answer
Shashi, fuel filter should have been replaced. Was it? If not replace it too. Other than that is there any check engine codes? If not go to auto zone and have them checked and cleared anyway since this service is free. Other than that switching gas stations or grades could cause this. Or driving frequency or habits as well.

There are no distributor caps or spark plug wires to replace. In 2001 Honda converted to a coil pack design which is geared to last the life of the car. If one of these coil packs fail you will know it.