What is the best fuel additive to combat ethanol problems?

I'm not trying to start a debate on ethanol fuels VS regular gas but speaking from experience I've noticed recurring problems in my vehicles running ethanol blend gas (10% ) . My toyota 4Runner I owned would not run on ethanol blend, it had to have 100% pure gas to avoid predetonation.

I'm facing a recurring problem of a slight miss in my wifes 2000 Toyota Camry and my 1997 Honda Accord (running a swapped engine on high octane.) When I run high octane race gas in my accord (105 octane, pure gas) it fixes the problem almost instantly for about 1000 miles. I obviously can't do this in my wifes Camry.

Everyone claims sea foam is the best to combat this problem but i'm seeking further input on the matter. Please, don't bash my statments, I'm going on personal experiences that ethanol blended fuel is bad for older vehicles and just want to figure out a way to "safely" run the blended fuel without having to buy oxygen sensors constantly and keep an eye on my injectors.

Why not just use premium ( 91 octane ) fuel? 91 octane, at least where I live, does not have ethanol added to it.

If you have pre-ignition it is not because of ethanol but because of carbon deposits in the cylinders (unless you have an ancient car, like pre-1980s). Knock sensors work very well on octane related detonation but can't help pre-ignition. The carbon deposits come from regularly using gasoline without enough detergent.

As a result of an EPA rule change in 1995 detergent levels in gasoline dropped about 1/3, producing the problem you are having. GM, Toyota, BMW and Honda recognized the problem (which was causing all sorts of warranty headaches) and collaborated to create the Top Tier consortium, created new standards for detergency in gasoline, then certified brands that met the new standards. The current list of qualifying brands is in the first source. If you stick with these brands (occasional odd tankfulls are okay) you will not have the deposit buildup.

I'm not a fan of Seafoam for a variety of reasons. Mopar Combustion Chamber Cleaner, available at Dodge dealers, is safer, cheaper, easier to use and more effective. The second source has the proper way to use it.