Bad gas mileage after new plugs and wires

[blackcorolla]

Hey guys,

So here's the story. I bought a 1993 Toyota corolla LE with 150 000km. So 1.8L 4 cylinder.... When i bought the car and drove it home i did a full clean up on it as everyone does when they buy a "new" car. One mistake i did was i engine de-greased the bay and washed it with a hose. Well when i started it back up it sputtered so i thought i got water down where the spark plugs are. So i unplugged the wires 1 too many times and used compressed air to get the water out. The last cylinder to the right after i pulled it, it wouldnt go down all the way, the wire on the inside of the boot was near the bottom of the boot. So i drove around like this for a week or two weeks and noticed a misfire at idle, very slight and when i put a great load on the engine. But i was still getting 460 km to tank as it drove like this. So i went ahead and ordered a new NGK TE-41 wire set and NGK spark plugs BKR5EYA (V-Power)

So i did the swap as perfect as i could, anti seize on the threads+ die electric grease on the boots. They came gapped but i checked the gap anyways. The plugs before were Denso K16R-U. Install went great. Car runs great, no misfiring at idle or on heavy load. BUT!!! i'm loosing like 60km per tank which is drastic as miles per gallon and pissing me off. Also i disconnected the battery after the install to reset the computer (based on other treads) What have i done wrong??? The NGK wires are considered performance wires, do they have to be matched with performance plugs? Please help Thanks, Allen

[96coroll]

On a full tanks what were you getting to begin with. And what has it dropped to?

[blackcorolla]

i was getting 460km per tank while it was misfiring slightly. So i figured after the new parts are installed id get close to 500. Instead im getting about 400km per tank.