Combating Carbon Build-up in BYD Engines

Here's an overview of BYD vehicle issues related to carbon buildup, injectors, EGR, DPF, and fuel systems, along with solutions and known models:
Carbon Build-Up issues
Cause:
- Lack of fuel washing over intake valves (direct injection design).
- Oil vapour recirculation from the PCV system.
Symptoms:
- Rough idle
- Misfires
- Reduced power
Note: Most BYD models (e.g., Atto 3, Seal) are fully electric, avoiding carbon buildup entirely.
Affected Models:
- Legacy combustion/hybrid models.
Solutions:
- Walnut blasting (for combustion engines).
- Oil catch cans (if applicable).
Injectors Issues
Cause:
- Clogging or electrical faults in fuel injectors.
Symptoms:
- Misfires.
- Poor acceleration.
- Hard starts.
Affected Models:
- Combustion/hybrid models.
Solutions:
- Ultrasonic cleaning or replacement.
- Premium fuel additives to prevent deposits.
Intake Manifold Issues
Cause:
Carbon/oil deposits in combustion engines.
Symptoms:
- Reduced airflow.
- Power loss.
Solutions:
- Manual cleaning during servicing.
EGR System Issues
Cause:
- Clogging from carbon/soot (combustion engines).
- Sensor failures (e.g., EGR temperature sensors).
Affected Models:
- Diesel/hybrid models.
Solutions:
- Regular EGR valve cleaning (manual or chemical).
- Sensor replacement (if faulty).
DPF Filter Issues
Cause:
- Clogging from incomplete regeneration.
- Short trips prevent passive regeneration.
Affected Models:
- Diesel models.
Solutions:
- Forced regeneration via diagnostic tools.
- DPF cleaning/replacement for severe blockages.
Fuel System Issues
Common Issues:
- The fuel pump leaks.
- Clogged filters from poor-quality fuel.
Affected Models:
Combustion/hybrid models.
Solutions:
- Filter/pump replacement.
- High-quality fuel use.
Solutions
- Walnut blasting: Mechanically clean intake valves every 50,000-80,000 km.
- Hydrogen carbon cleaning: Non-invasive method for removing deposits.
- Use high-quality, Top-tier fuel to minimise carbon buildup.
- Perform regular “Italian tune-ups” (high-speed highway driving) to help burn off deposits.
- Clean the EGR valve periodically to prevent clogging and maintain proper exhaust gas recirculation.
- For diesel models, ensure proper DPF regeneration through highway driving or DPF Filter cleaning.
- Regular maintenance, including oil changes and filter replacements.
Preventative Measures
Carbon Build-Up Related OBD-II Diagnostic Trouble Codes
The following OBD-II codes may indicate carbon buildup issues in your engine.
Use our searchable table to identify and address potential problems:
Code | Description | Symptoms | Affected System |
---|---|---|---|
P246C | Diesel Particulate Filter - Soot Accumulation for Bank 1 | Check engine light | DPF |
P246B | Diesel Particulate Filter - Soot Accumulation for Bank 2 | Check engine light | DPF |
P2463 | Diesel Particulate Filter Restriction - Soot Accumulation | Check engine light, reduced power, limp mode activation | DPF |
P2459 | Diesel Particulate Filter Regeneration Frequency Too High | Check engine light | DPF |
P2458 | Diesel Particulate Filter Regeneration Duration Too Long | Check engine light | DPF |
P244A | Diesel Particulate Filter Differential Pressure Too Low | Check engine light | DPF |
P242F | Diesel Particulate Filter Regeneration Incomplete | Check engine light, poor acceleration | DPF |
P2176 | Throttle Actuator Control System - Forced Limited Power | Reduced power, check engine light | Manifold |
P2008 | Intake Manifold Runner Control Stuck Closed | Check engine light, poor acceleration | Manifold |
P2007 | Intake Manifold Runner Control Stuck Open | Check engine light, rough idle | Manifold |
P2006 | Intake Manifold Runner Control Actuator Performance Problem | Similar to P2004 symptoms | Manifold |
P2004 | Intake Manifold Runner Control (IMRC) Actuator Range/Performance Problem | Check engine light, reduced engine performance | Manifold |
P2002 | Diesel Particulate Filter Efficiency Below Threshold (Bank 1) | Check engine light, reduced fuel efficiency, possible limp mode | DPF |
P0421 | Warm Up Catalyst Efficiency Below Threshold (Bank 1) | Similar to P0420 symptoms | Carbon Build-Up |
P0420 | Catalyst System Efficiency Below Threshold (Bank 1) | Check engine light, failed emissions test | Carbon Build-Up |
P0404 | EGR Control Range/Performance Problem | Check engine light, rough idling, hesitation in acceleration, poor fuel economy | EGR |
P0403 | EGR Control Circuit Malfunction | Check engine light | EGR |
P0402 | EGR Flow Excessive | Check engine light, surging at idle | EGR |
P0401 | EGR Flow Insufficient | Check engine light, engine knocking, poor acceleration | EGR |
P0400 | EGR Flow Malfunction | Check engine light, rough idling, reduced power | EGR |
P0304 | Cylinder 4 Misfire Detected | Similar to P0301 symptoms | Carbon Build-Up & Injector |
P0303 | Cylinder 3 Misfire Detected | Similar to P0301 symptoms | Carbon Build-Up & Injector |
P0302 | Cylinder 2 Misfire Detected | Similar to P0301 symptoms | Carbon Build-Up & Injector |
P0301 | Cylinder 1 Misfire Detected | Rough running, poor acceleration | Carbon Build-Up & Injector |
P0300 | Random/Multiple Cylinder Misfire Detected | Rough idle, engine shaking, reduced power | Carbon Build-Up & Injector |
P0230 | Fuel Pump Primary Circuit Malfunction | Hard starting, stalling while driving | Fuel System |
P0206 | Injector Circuit Malfunction - Cylinder 6 (if applicable) | Similar to P0201 symptoms | Injector |
P0205 | Injector Circuit Malfunction - Cylinder 5 (if applicable) | Similar to P0201 symptoms | Injector |
P0204 | Injector Circuit Malfunction - Cylinder 4 | Similar to P0201 symptoms | Injector |
P0203 | Injector Circuit Malfunction - Cylinder 3 | Similar to P0201 symptoms | Injector |
P0202 | Injector Circuit Malfunction - Cylinder 2 | Similar to P0201 symptoms | Injector |
P0201 | Injector Circuit Malfunction - Cylinder 1 | Check engine light, rough idle, poor acceleration | Injector |
P0200 | Injector Circuit/Open | Active check engine light, engine misfires, rough running | Injector |
P0183 | Fuel Temperature Sensor Circuit High Voltage | Check engine light; possible performance issues | Fuel System |
P0182 | Fuel Temperature Sensor Circuit Low Voltage | Check engine light; possible performance issues | Fuel System |
P0174 | System Too Lean (Bank 2) | Increased fuel consumption and decreased performance | Fuel System & Injector & Manifold |
P0172 | System Too Rich (Bank 1) | Black exhaust smoke, poor performance, increased fuel consumption | Fuel System |
P0171 | System Too Lean (Bank 1) | Check engine light, poor acceleration | Carbon Build-Up & Fuel System |
P0106 | Manifold Absolute Pressure (MAP) Sensor Range/Performance Problem | Check engine light, poor acceleration, rough idle | Manifold |
P0101 | Mass Air Flow (MAF) Sensor Range/Performance Problem | Check engine light, reduced power, poor fuel economy | Manifold |
P0093 | Fuel System Large Leak Detected | Check engine light, rough running, decreased performance | Fuel System |
P0090 | Fuel Pressure Regulator Control Circuit Malfunction | Check engine light, poor fuel economy | Fuel System |
P008B | Low Pressure Fuel System Pressure - Too High | Check engine light, rough idle, reduced power | Fuel System |
P008A | Low Pressure Fuel System Pressure - Too Low | Check engine light, poor acceleration, engine stalling | Fuel System |