P0430 — Catalyst System Efficiency Below Threshold Bank 2
Seen on: Heavy Truck/Diesel
Catalyst System Efficiency Below Threshold Bank 2. Common causes: Catalyst contaminated or damaged.
Your code rides along, so nearby mechanics see the fault before they quote you.
How serious is it?
Serious. Power derate likely — plan to stop soon.
Most likely causes
- Catalyst contaminated or damaged
- Engine oil consumption
- coolant leak to exhaust
First moves (roadside)
- Inspect exhaust for oil residue
- check coolant level trend
FAQ
Catalyst System Efficiency Below Threshold Bank 2. Common causes: Catalyst contaminated or damaged.
Serious — Power derate likely — plan to stop soon.
The most common cause is: Catalyst contaminated or damaged. Other possibilities include Engine oil consumption; coolant leak to exhaust.
Power derate likely — plan to stop soon. When in doubt, get a qualified mobile diesel tech on the truck before continuing.
Find a mechanic or related guides
General diagnostic guidance for diesel engines (Cummins, Detroit, PACCAR, Volvo, Mack and more). Not a substitute for a scan-tool diagnosis on your specific truck.