About to undertake the ATF treatment for the first time.

New cats installed on my 84 less than 1 year ago. Don't want to guck them up b4 my final emissions test next spring.

Is the ATF treatment a cat killer?

 

No, spark plug killer.

 

Why don't you take off the cat while doing the ATF tricK? Not hard unless your very lazy? Sure it will be loud, but what the hell? Do you live in a big city? If so, your going to be making a big smoke cloud, might as well be very loud? Then install new spark plugs afterwards, and call it a day...

 

Exhaust manifold flange is slightly warped and I had a bitch of a time getting a proper seal when new cats installed. Would rather not open up that can of worms until ready to go with headers, cat free and free flowing exhaust...so I ask again...does the ATF gum up the cats?

 

arrexeven,
I did the ATF on my 86 Base model. When I got done my cats would glow red hot whenever I ran the car. I can't swear the ATF ruined the cats, but I have a reasonable suspicion that is what happened. Now, every time I do the ATF I disconnect the cats. They are too expensive to risk ruining. If you are going to risk it, make sure that you don't use too much ATF. It ignites in the exhaust system (don't ask how I know this), so the more you use the more likely it is that you will toast your cats.
Oh yeah, you will also be able to find any holes in your exhaust system, just look for the flames. My advice is to have a fire extinguisher handy.
of course that's just my opinion, I could be wrong,
hanman

 

No Hanman, your damn right. Cats are designed for raw CO, HC, and O2 to work right. When ever you introduce other eliments like Heavy long strain molucules found in the Autotranny fluid, they will bond to the cat and make them clug out and become ineffective. The ATF trick is for people who don't have cats on only. OR take them off during this. Get a new gasket and reinstall them! ITs not hard....

 

what about presilencers.?? are those kosher?

 

Switch to MMO

 

mmo is the plugs?

 

So, Pele, I've heard a lot about MMO (short for Marv's Mystery Oil?). Are you saying that it works the same as ATF treatment, without damaging the cats?

Any idea if it's available in Canada?

 

I would not do either one, ATF or MMO, without removing the cats. It's just too easy a job to risk ruining them.
I have not tried MMO, only the ATF. I have not had good success with it mainly because of the problem with car. I could tell on one of them that it did help compression.
If you have stuck apex's in the rotor, ATF will help. Bad side seals etc, it won't do a thing.
I know the ATF has detergents in it that help loosen the carbon crud from the rotor. This is what makes it work. If MMO has similar or same detergents then it would work the same way.
DISCONNECT THE CAT!.
just my opinion, I could be wrong,
hanman

 

Let me try this again. I mentioned ATF and MMO are almost identical but the post didn't err post.
There was a long thread on this at mazspeed.com. someone actually ran through the chemical/ingredient list somehow by calling the man. or distributor. The results were posted and the ingredient lists look very similar.
I use ATF in the engine, MMO in the oil and fuel.

 

The cats will come off. Hope the wonky manifold flange permits easy reconnection.

My own cats will be safe, but neighbourhood tabbies better hold on to their nads when I start this puppy up.

 

Oh, another question...Should engine be warmed up or stone cold when the ATF goes in?

 

Has anyone ever used amsoil power-foam to de-carbon their engine??

 

It doesnt' matter if it's hot or cold. But, it is much easier to work on when it's cold. Put the atf either in the carb, or in the leading plug holes.
hanman

 

Canadian Tire Sells it. It's in the fuel additive section, and comes in a little red bottle.