Guide

Signs your chipper's catalytic converter is failing

On a wood chipper, the catalytic converter slowly loads up with carbon and soot until it chokes exhaust flow. When that happens the engine can't breathe, and you feel it in performance long before you ever see smoke. Here's what to watch for — and how to confirm it's the cat before you spend on a new OEM unit.

Five common signs

Down on power

Bogs under load, slow to recover after a big feed.

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Won't hit rated RPM

Can't reach or hold full engine speed.

Cat code or Tier 4 derate

On newer diesels, a plugged cat often shows as a derate first.

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Running hot

Restricted exhaust traps heat you can feel at the outlet.

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Rattle or melt-down

A rattling or partially melted substrate is done — rebuild it.

How to confirm it's the cat

Pro tip to avoid a comeback: before you install the rebuilt unit, check or replace the O2 sensor and decarbonize the engine. Doing that eliminates the large majority of early cat failures and repeat visits.

Confirmed it's the cat? You don't need OEM.

If the housing is intact, the converter can almost always be rebuilt — a fresh substrate goes into your original housing for about half the cost of a new OEM unit, built to meet EPA emissions standards and backed by a warranty against manufacturing defects. Turnaround is 3–5 business days on a core exchange.

Compare rebuild vs. replace →

Think it's your cat? Let's price a rebuild.

Send your machine and engine — or a photo of the converter — and we'll confirm and quote.

Request a quote ☎ 774-701-6374