Cleaning Catalytic Converters?

[Loobed]

I was reading somewhere (?) that it is possible to clean a catalytic converter (cat) by getting it hot enough to boil off any metallic contaminants. Lead is not a problem because there isn't any lead in gasoline. Zinc and Phosphorus contaminants are what I would like to remove. A modern cat's running temperature is 1200 to 1600 *F. Phosphorus boils at under 600*F, and Zinc boils at under 1700*F. Both of those boiling points are for the substance in their elemental state; In compound form (ZDDP) them may have a higher boiling point. Does anyone know what I could do, or maybe add to gasoline, to raise the temperature of the cats, temporarily, above 1700*F? I know running the engine hard under load can do it, but I don't have an area (open highway) available where I can do that. I read that increased amounts of fuel in the exhaust can cause the cats to get very hot (and melt). I was wondering if I could set up a propane torch, not lit, near my smog air pump inlet, and then turn on the air pump manually to pump unburnt propane into the exhaust system and into the cats? Propane seems like the cleanest fuel to add to the exhaust. will Acetone, MEK, Toluene, or some other chemical added to the gasoline make the cats run hotter?

 

[OVERKILL]

Significantly retarding the timing will do it.

 

[ahoier]

What are you trying to achieve....? I've heard great stuff about the CRC product "Guaranteed to Pass" apparantly it's got a high concentration of PEA to burn up and clean anything that should be cleaned, resulting in better emissions.....or would that be "lower" emissions...?

 

[Loobed]

Originally Posted By: ahoier

What are you trying to achieve....? I've heard great stuff about the CRC product "Guaranteed to Pass" apparantly it's got a high concentration of PEA to burn up and clean anything that should be cleaned, resulting in better emissions.....or would that be "lower" emissions...? :P

I am trying to boil off any metalic crud like ZDDP on/in the cats. PEA is a detergent that works on carbon. It cleans the injectors, valves and rings. PEA does not clean the cats (AFAIK). OVERKILL, I can't retard the timing, my truck is a 2001 with a crank censored computer controlled ignition.

 

[LeakySeals]

Lacquer thinner. Laundry detergent bath. Scotty Kilmer's the big dog!

 

[CourierDriver]

Now it appears that some of us have way to much time on our hands when doing metallurgy. at a plus 1700 degrees u might just find a wad of melted metal for cc, imho. I could be wrong, it has happened before, I think.

 

[ARB1977]

Don't want to run it too long under load. When I moved 1500 miles away I towed and ran my Tacoma in third gear the whole way. By the time I got to Texas I melted an exhaust rubber hanger, lol. My cats should be nice and clean.

 

[JHZR2]

Ever think about what temperature Pt, Pd, Ir, Rh boil at? Might just knock them off too... The best you can do without a lot of (nasty) chloride chemistry is to burn off the sulfides.

 

[dailydriver]

Originally Posted By: Loobed

OVERKILL, I can't retard the timing, my truck is a 2001 with a crank censored computer controlled ignition.

You actually could with a hand held tuner, BUT, this would have a cost at least approaching (if not more than, depending on your vehicle) a set of brand spanking new Cali-spec catcons!

 

[antiqueshell]

Actually you can pretty easily change the timing by disconnecting the MAF sensor and physically adjusting the distributor body to retard timing. Actually with my car if you simply disconnect the MAF the car will run in open loop mode and this causes it to run rich..just enough to heat the cats up above normal and burn off contaminates. Maybe disconnect the MAF drive it this way for few hours and then reconnect. You can actually smell the cat running hot with the open loop mode in effect.

 

[TFB1]

Originally Posted By: antiqueshell

Actually you can pretty easily change the timing by disconnecting the MAF sensor and physically adjusting the distributor body to retard timing.

That ain't happnin', because few vehicles of the last 15 years even have a distributor... If they are crank triggered as the OP mentioned his is, moving the distributor only changes the position of the cap tower in relation to the rotor... Makes no change in timing at all...

 

[artificialist]

Originally Posted By: TFB1

Originally Posted By: antiqueshell

Actually you can pretty easily change the timing by disconnecting the MAF sensor and physically adjusting the distributor body to retard timing.

That ain't happnin', because few vehicles of the last 15 years even have a distributor... If they are crank triggered as the OP mentioned his is, moving the distributor only changes the position of the cap tower in relation to the rotor... Makes no change in timing at all...

Yes, a GM 5.3 is a distributorless ignition, it has one ignition coil per cylinder. Reprogramming the computer would be the only way to retard timing. Anyway, I saw a product at Pep Boys that was called "Catacleen" and it said it was to cure catalytic converters. I don't know if it actually works.

 

[mechtech2]

There is not much we can do to clean cats. Partially, because there are so many ways they can be faulty or restricted. You could try a cat clean product, but don't expect miracles.

 

[LeakySeals]

Originally Posted By: mechtech2

There is not much we can do to clean cats. Partially, because there are so many ways they can be faulty or restricted. You could try a cat clean product, but don't expect miracles.

You dissin my link?

 

[GMBoy]

What symptoms or codes are making you want to "clean" you cat. converters??? This is not a maintainable or cleanable part. As long as your car is running correctly and no damage is done - you do nothing. If it has been damaged - you replace it.

 

[TFB1]

Originally Posted By: LeakySeals

Originally Posted By: mechtech2

There is not much we can do to clean cats. Partially, because there are so many ways they can be faulty or restricted. You could try a cat clean product, but don't expect miracles.

You dissin my link?

LOL, Scotty is a sharp dude, if he says cleaning works I believe him...

 

[yonyon]

Originally Posted By: artificialist

Reprogramming the computer would be the only way to retard timing.

Not necessarily. These still have shose short little ignition secondary wires, right? You could pick up one of those cut to length ignition wire kits and make a very long one. One should be enough. Make it long enough so you can use a bit of fish wire and route the ignition wire down by the knock sensor wire and run it parallel to the wires from the knock sensor for a ways. Aluminum core ignition wire sould work better than carbon for this. Also, if you just want to get the cat good and hot, disconnect the upstream O2 sensors and the temperature sensor. If you don't want to carbon up your O2s, take them out and put plugs in instead. For a little more heat, disconnect the electrical connector on two fuel injectors opposite each other in the firing order 1&6; 8&5; 7&4; 2&3. The rich running will add fuel to the exhaust and the unfueled cylinders will pump in air for some good fire in the catalyst. I don't know if this will clean your cats, but it'll certainly heat them up. Run it like that long enough and under some decent load and you should be able to make some plenty good melted slag of the "used to be a cat" variety.

 

[TFB1]

Originally Posted By: yonyon

Originally Posted By: artificialist

Reprogramming the computer would be the only way to retard timing.

Not necessarily. These still have shose short little ignition secondary wires, right? You could pick up one of those cut to length ignition wire kits and make a very long one. One should be enough. Make it long enough so you can use a bit of fish wire and route the ignition wire down by the knock sensor wire and run it parallel to the wires from the knock sensor for a ways. Aluminum core ignition wire sould work better than carbon for this.

LOL that's bogus as [censored], electricity inside a cable travels at over 100,000 miles per second... To make any appreciable difference, you'd need enough cable to stretch around the earth... If it were possible, voltage would need to be increased several thousand times so there would be enough to produce a spark at the other end...

 

[Loobed]

Originally Posted By: GMBoy

What symptoms or codes are making you want to "clean" you cat. converters??? This is not a maintainable or cleanable part. As long as your car is running correctly and no damage is done - you do nothing. If it has been damaged - you replace it.

No symptoms, and no codes. I was just reading something about boiling off the metals on the cats, and wondered if it could be done, or how it could be done.

 

[yonyon]

Originally Posted By: TFB1

Originally Posted By: yonyon

Originally Posted By: artificialist

Reprogramming the computer would be the only way to retard timing.

Not necessarily. These still have shose short little ignition secondary wires, right? You could pick up one of those cut to length ignition wire kits and make a very long one. One should be enough. Make it long enough so you can use a bit of fish wire and route the ignition wire down by the knock sensor wire and run it parallel to the wires from the knock sensor for a ways. Aluminum core ignition wire sould work better than carbon for this.

LOL that's bogus as [censored], electricity inside a cable travels at over 100,000 miles per second... To make any appreciable difference, you'd need enough cable to stretch around the earth... If it were possible, voltage would need to be increased several thousand times so there would be enough to produce a spark at the other end...

The idea is to generate a false knock signal.