hesitation problems

[lennard]

I would like to thank everybody who posted solutions to hesitation problems on Avalons. Suffered about 3 weeks trying to find out what's wrong. Started changing ignition cables then spark plugs. Then my mechanic suggested to have the coil packs checked. But reading some of the experiences by Avalon owners here I decided to change the coil pack myself and totally solved the problem.

Just one question whats the difference between a Toyota Platinum spark plugs with two grounds (or whatever that thing at the end is called) and a Toyota Iridium with a single ground? Tnx again

[toyomoho]

Thought plug type usage depended on the type of ignition system used. Many later model cars ignition systems fire every crank revolution with one spark being wasted. The polarity of the plug voltage might also change. If a single ground electrode plug is used it will wear out twice as fast with this system, hence the use of a double ground.