Your probably correct. I am just trying to brainstorm as the possibles for melting down the cat. :-)

The usual culprit is a lack of service around spark plugs and older vehicles. With the introduction of widespread fuel injection somehow people forgot to maintain their cars I guess. I've ran into this maybe a half dozen times or so with older gasoline rigs of various makes. Especially true with Subaru and Toyota or any machine that utilizes waste spark technology. Not as much of an issue around GM as they went to high energy ignitions and high quality delco spark plugs pretty early on.

This current 99 4Runner that I have has the same issue. Bought it cheap because I didn't run right, and it really needed was a tuneup. The plugs were worn out beyond belief. The problem with that is that you can create an incomplete burn situation, and it doesn't take a whole lot of extra fuel load to take the converters beyond their threshold and cook them.

Any easy test to see if your converters are fried is if the downstream pipe temperature is higher than the upstream inlet pipe temperature using an infrared thermometer.

Assuming you're only looking through one converter, and your vision is not obstructed by a pipe bend, you should be able to observe light passing through some what.

If your trying to look through both converter's at the same time I doubt you'll see anything.

I personally haven't had any success with it the two vehicles i've tried it in. A friend of mine that turned me onto the product is about 3 for 5 for success on it.

I think if it will work, it's certainly a cheap product. I have a feeling it has to do with the fact that if the metals inside the converter have been damaged due to excessive heat, it probably won't work. If it's just dirty or partially clogged due to contaminants, but hasn't been overheated, it may work.

It's worth a shot for sure.

Heck Tetanus 1 actually had an spark plug electrode snap off and parts of it are still in the piston ( Before i owned it) The PO thought he was loosing rod or something. When he caused it by not changing the plugs. I see wear on the plugs are gone... You know how long that would take to cause that. Probably the original plugs in 215K...lol

Don't complain too much, premium is $5.50 here where I live and I have to run it. I know you don't pay that much for premium in Georgia!

I hope your grandpa is getting the best care that he can as that's a tough diagnosis. I don't know if it's possible or not but try and spend as much quality time with him as you can. Lots of great stories and life advice can be gained from those that have lived long lives before us.

I was a premium user in my 97 until CA gas prices went super high a couple years ago. I tried the "mid grade" as an experiment and so far it's been fine. Regular always caused a light pinging when accelerating uphill.

The only thing I can think of, is that time I one of the ignition coils died on a trip and I was forced to carefully drive for a while to get closer to home and to a shop. Other than I cannot think of anything.

Well, I know newer cars are "supposedly" designed to handle ethanol. But for cars from the 90s I think they "claim" they can, but it still does harm.

Premium is around... $4.00 to $4.30 depending on where you go. I just get non-ethanol now which is around the same price, but Non-Ethanol has value, in my mind where as premium does not. (Unless you actually need it for high compression)