18 Wheeler Catalytic Converter Scrap Value: DPF, DOC and SCR

A single aftertreatment can off a Class 8 truck is worth roughly $15 to $806 as scrap, depending on whether it is a DOC, a catalyzed DPF or an SCR unit, and on the part number stamped in the shell. Rockaway Recycling listed DPF units at $30 each at the low end and up to $758 on 21 August 2026, with diesel cats starting at $15 and topping out near $477–$511. But scrap is almost never the right answer on a straight, uncracked DPF: a used Paccar MX–13 DPF assembly was listed at $2,349 in August 2026, and a reman Cummins ISX filter carries a $700 refundable core charge all by itself.

What is actually hanging off the frame rail

Post–2007 and especially post–2010 Class 8 trucks carry three separate catalyzed devices. People call the whole box a catalytic converter. It is not one part. Know which one you are holding before you quote it.

DOC — diesel oxidation catalyst

First in the flow. It burns off carbon monoxide and unburned hydrocarbons and makes the heat that regenerates the filter behind it. This is the platinum–richest piece in the system. Research published in the journal Metals in December 2021 measured DOC substrates at 2,900–3,000 ppm platinum. Small, dense, valuable.

DPF — diesel particulate filter

The big one. Wall–flow ceramic that physically traps soot. The same 2021 Metals study put catalyzed DPF substrates at 1,600–1,700 ppm platinum — about half the DOC loading by weight, but the substrate is far larger, so total metal can be similar or higher. Most of a DPF assembly is stainless shell and insulation. Do not price it by the bathroom scale.

SCR — selective catalytic reduction

Last in line. It uses DEF to knock down NOx. The chemistry is vanadium or copper–zeolite on most platforms, not PGM heavy. ScrapMonster warned in its 6 August 2026 identification guide that assuming gasoline converter composition on an SCR unit is a common and expensive mistake. Many SCR bricks are worth stainless value and little else.

Current per–unit scrap values

These are published buyer guidelines as of 21 August 2026. They are ranges because the spread inside each category is enormous — a low–grade and a high–grade unit in the same category can differ twenty times over.

Note the disagreement. ScrapMonster carries a flat $13 diesel converter number while Rockaway and RRCats show ranges reaching into the hundreds. These are not measuring the same thing. The flat number is a bottom–of–category placeholder for unidentified material. The wide ranges reflect what a graded, part–numbered unit brings.

The Red Fox spread is the important line. A specialist processor quoting $20–$700 against a general yard paying $0.50–$3.00 for the identical part is the whole game. General yards pay shell value because they cannot refine PGMs. Sell aftertreatment to somebody who assays.

Why diesel is a platinum story, not a rhodium story

Gasoline three–way converters need rhodium to reduce NOx in a stoichiometric exhaust stream. Diesel runs lean, with oxygen to spare, so rhodium does very little. Diesel oxidation chemistry runs on platinum, with palladium sometimes substituted or added. That single fact explains most of the value gap between a modern gas cat and a truck DOC.

Rhodium is worth five times platinum per gram. A diesel unit has almost none of it. That is why a small hybrid cat can beat a truck DOC weighing ten times as much.

How much platinum is really in there

A March 2026 breakdown from Xerodrive put heavy–duty diesel converters at 5.0 to 12.0 grams of platinum per unit, against 0.5–1.5 g for a domestic gasoline car cat. At the 21 August 2026 spot of $60.35 per gram, 5 to 12 grams of contained platinum is roughly $300 to $725 of metal at spot.

You will not be paid that. Refining loss, assay cost and processor margin all come out first, and spot is the ceiling rather than the offer. Use the spot math as a sanity check on whether a quote is insulting, not as an expected price.

The decision that actually matters: resale or scrap

This is where most people leave money on the ground. There is a large, active market for whole DPF assemblies that has nothing to do with precious metal recovery. Fleets need filters. A used or reman assembly is worth many times its metal content.

Read that table twice. A core a remanufacturer will accept is worth $700 as a core. The same filter shredded for platinum might bring $30 to a couple hundred. The core route wins unless the substrate is destroyed.

When to scrap instead

• Substrate is cracked, melted or has blown a channel. A reman house will reject it. Now it is metal.
• Face is ashed solid and will not clean. Cleaners test before and after; a failed unit becomes scrap.
• Shell is rotted through or the flanges are gone.
• You cannot identify it and no processor will bid on an unknown.

When to sell it whole

• The filter still holds pressure and the substrate is intact.
• You have the part number and it is a common platform — Cummins ISX and X15, Detroit DD13 and DD15, Volvo D13, Paccar MX–13.
• Sensors, clamps and gaskets are still attached. Sensors carry real standalone value.
• A reman supplier is running a core program on that number. Call and ask before you cut anything off.

Brand notes from the yard floor

No public source publishes a reliable brand–by–brand scrap table for Class 8 aftertreatment. Red Fox Resources says plainly that it does not publish per–part pricing and quotes from part numbers instead. What is documented is that common platforms have the deepest core markets.

• Cummins ISX and X15 — the largest core pool in North America. Reman and new filters are widely stocked. Best odds of beating scrap.
• Detroit DD13, DD15, DD16 — later trucks use a combined one–box unit packaging DOC, DPF and SCR together. Do not cut a one–box apart before you get it quoted whole.
• Volvo D13 and Mack MP8 — shared architecture, steady core demand, inlets and outlets often sold separately.
• Paccar MX–13 — the Kenworth and Peterbilt volume engine, with a used assembly market documented above at over $2,000.

How not to get shorted

• Photograph the stamped part number and serial before anything moves. Every serious buyer prices from that number.
• Shell and insulation dominate the weight. ScrapMonster said it directly on 6 August 2026: size and weight are unreliable value indicators.
• Get two quotes. Published ranges are guidelines and no yard is obligated to honor them.
• Never accept a per–pound offer on a catalyzed unit. Per–pound is a shell–value offer.
• Keep DOC, DPF and SCR separated and labeled. Mixed lots grade down to the worst piece.
• Check the reman core market first. Every time.

Precious metal prices move daily and converter buy prices follow with a lag. Every figure above is a snapshot from the date listed, not a quote. Confirm with your buyer before you cut anything off a truck.

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