I just installed NGK Iridium spark plugs in my Honda Accord 2000 SE, man its amazing, its fast, but idle rpm came to very low and motor start to shake a bit.
Then I followed your another post how to reset ECU, yp I removed my nagative end from the battery and wait for 10min and reconnected and start the engine and let the idle speed for another 7-10 mins, and stop the engine and wait 5min
Drive around the house about 5min in 4th,3rd,2nd,and reverse gear, the put the machine on to the HWY-401 East, did around 100,120,160 and 180 for 20 minitues, oh man I can already see improve acceleration, and fuel efficiency
then stop, now I can see my idle speed came to normal + 2 notch up, thats good no more shake (virebrate)
I didn't have no clue about how to tune my car, Mike thank you so much for this great information, and sorry about my English
Joe
