For the grand am cat, if it's a square-ish shape that's narrower on the top than on the bottom, it's called a breadloaf. They're currently at $83 here. If it's a round cat that has a 3/8" flange of metal running down each side, that's called a large flow. Up here those are graded as either AC 4-dot or medium GM, depending on the buyer and your relationship with them. Prices for those are from $83 to $102. On the diesel cats; if it's 2007 or older, they're pretty cheap, especially when you consider how big they are. The older Fords and Dodges are currently going for around $25 here, while the GMs are at $5. A couple of the buyers will just lump them all together and pay $10 on any older diesel. On the newer diesels, '08 and up, they are worth quite a bit. The 3-piece Dodge systems (foil pre, diesel particulate filter or DPF, and the converter) sells for anywhere from $450 up to $800 depending on the part numbers. On those, the 2008-9 models are the best, with the newer ones being the cheaper ones. The Ford systems, which consists of a DPF and the converter bolted together in a single assembly, sell for $225. The GM systems, which are a smaller pre in front of the DPF, sell for about $200. On the 2012 and newer systems, I've only seen a few of the Dodges and Fords, which are currently going for $250. They are all a single assembly now, no more multiple separate pieces on the exhaust pipe. One way to tell if the cat you have is a newer expensive one vs. an older cheap system; the newer systems have small stainless steel fuel lines (about 1/4") plumbed into the exhaust for the emission "purge" system, while the older ones do not. As well, the newer ones use O2 sensors while the old ones don't.
-edit- forgot to add, on the Grand Am, if it's a round cat that doesn't have the 3/8" flat flange/seam of metal running down each side, and instead just has smooth sides, that's graded as an AC 4-dot, which is the $83 cat.
Bookmarks