I just removed my nearly new stock exhaust system on my 96 and am looking at what some call the soot trap and the inside looks an awful lot like a cat. I do have the f vin engine which is not supposed to come with a cat. I am wondering if the dealer I bought it from replaced the exhaust system with an s code style. How do I tell the difference just by looking at it?

The reason I ask is I will be trying to sell the old system and have no idea what, if any, the price difference would be for a cat vs a soot trap. Any help would be greatly appreciated! Just installed straight pipe for cheap and need to get rid of the nearly new (15,000 mi) old system, behind downpipe.

Thanks

Will