Cat Converter Honeycomb

**hills** · 09-16-2018, 10:48 AM

Originally Posted by APA

Country roads and interstate driving..... I don’t see the logic of how that determines the recovery. Cars have air filters and it’s run threw the engine.

It does seem kind of farfetched.

Just for the sake of argument : Could it be that the air being introduced on the upstream end of the cat by the air pump (smog pump) isn't run through the air filter first ?

I can't remember how the thermactor system piping is run. Haven't had to deal with one in awhile.

Edited to add: Ahh ... i just remembered. It's not that uncommon for the metal air tube that goes from the air pump to the cat to corrode out and break off.

That would most definitely cause the cat to draw in bad air and every bit of road crap that's down under the vehicle. Road sand, rain, snow,slush, road salt ... you name it.

**APA** · 09-17-2018, 05:48 AM

Less than 1-2% of catalytic converters have an “air pipe” going to it.

Originally Posted by hills

It does seem kind of farfetched.

Just for the sake of argument : Could it be that the air being introduced on the upstream end of the cat by the air pump (smog pump) isn't run through the air filter first ?

I can't remember how the thermactor system piping is run. Haven't had to deal with one in awhile.

Edited to add: Ahh ... i just remembered. It's not that uncommon for the metal air tube that goes from the air pump to the cat to corrode out and break off.

That would most definitely cause the cat to draw in bad air and every bit of road crap that's down under the vehicle. Road sand, rain, snow,slush, road salt ... you name it.

**hills** · 09-17-2018, 09:50 AM

Originally Posted by APA

Less than 1-2% of catalytic converters have an “air pipe” going to it.

True enough. Most of my experience has been w/ Ford Vans & Pickups.

Thing is ... there generally needs to be some means of pressurized fresh air induction upstream of the cat.That's oftentimes done with a smog pump aka air pump. The air pumps tend to have their own air intake and filtering system.

Not that it matters all that much. It's still a pretty thin argument when they say country driving is harder on a cat than city driving. It's hard to figure out why that would be so.