What is a pre catalytic converter?
 

As the title says What is a pre catalytic converter. My mid pipe on my 90gt looks like it has the cats removed but there are still catalytic converter looking things up closer to the headers. Any help would be great.

Re: What is a pre catalytic converter?
 

There are 4 catalytic converters on your car, but that's less than the 6 found on SN95 5.0s.

Anyway, from my understanding, the pre-cat's job is reduce and break up the nitrogen oxides in the exhaust, while the main cat's job is to oxidize the hydrocarbons and convert the carbon monoxide to carbon dioxide.

The pre-cat's essentialy make the job easier for the main catalytic converters.