SCR NOx Catalyst Over Temperature Bank 2
The P20F0 code indicates that the Selective Catalytic Reduction (SCR) catalyst temperature on Bank 2 has exceeded the maximum allowable limit. This typically occurs due to excessive exhaust temperatures, often from over-fueling, a clogged DPF, or a malfunctioning SCR system. Prolonged overheating can damage the catalyst, leading to reduced NOx conversion efficiency and potential engine performance issues.
01. Most Common Causes
- Excessive exhaust temperature due to over-fueling or injector issues
- Clogged Diesel Particulate Filter (DPF) causing backpressure
- Faulty SCR catalyst or temperature sensor
- Engine misfire or timing issues
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine power or limp mode
- Increased exhaust smoke (black or white)
- Poor fuel economy
03. Step-by-Step Diagnosis
Step 1: Scan for additional codes and check freeze frame data.
Step 2: Inspect the SCR catalyst and temperature sensor for damage or corrosion.
Step 3: Check DPF pressure differential and regeneration status.
Step 4: Monitor exhaust temperature readings with a scan tool while driving.
Step 5: Inspect fuel injectors and engine timing for over-fueling causes.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as overheating can damage the SCR catalyst and other exhaust components. Limp mode may activate, reducing power.
How much does it cost to fix?▼
Diagnosis typically costs $50-$150. Repairs can range from $200 for a sensor replacement to $2,000+ for a new SCR catalyst.