Fuel Injectors are precision-engineered components that deliver the right amount of fuel to your engine under all operating conditions. Controlled by the vehicle’s Powertrain Control Module (PCM) or Engine Control Unit (ECU), each injector atomizes fuel into a fine mist, ensuring the correct air-fuel mixture for efficient combustion, performance, and reduced emissions.
There are three main types of injectors used in modern vehicles:
- Throttle Body Injection (TBI): Sprays fuel into the throttle body for distribution to all cylinders.
- Port Fuel Injection (PFI): Delivers fuel directly into each intake port, providing more precise fuel metering.
- Direct Injection (DI): Operates at extremely high pressures, injecting fuel directly into each cylinder for maximum efficiency and power.
Regardless of the system, all fuel injectors perform one crucial role — to ensure optimal fuel atomization for smooth operation and lower emissions.
How It Works:
Each fuel injector is an electronically controlled valve designed to open and close in milliseconds based on signals from the vehicle’s ECU.
- When commanded, the injector opens to allow pressurized fuel to pass through its tip.
- The fuel is atomized into a fine mist for even combustion.
- The ECU continuously adjusts injector pulse width based on sensor data, including oxygen, air temperature, and mass airflow readings.
This constant feedback loop allows your engine to maintain the perfect air-fuel ratio, improving fuel efficiency and drivability.
Product Features & Benefits from Walker Products:
- Exact OE Fit: Direct replacement injectors designed for proper fit, form, and function.
- OE Replacement Quality: Meets or exceeds OEM standards for flow rate, spray pattern, and durability.
- Precision Atomization: Engineered nozzle design ensures fine, consistent fuel spray for efficient combustion.
- Corrosion-Resistant Construction: Built to withstand ethanol and fuel additives.
- Improved Performance: Restores smooth idle, acceleration, and fuel economy.
- Comprehensive Coverage: Available for TBI, PFI, and Direct Injection systems.
Symptoms of a Failing Fuel Injector
- Hard starting or no start.
- Rough idle or engine surging.
- Loss of power or hesitation during acceleration.
- Reduced fuel efficiency.
- Check Engine Light (CEL) illuminated.
When one or more injectors malfunction, the air-fuel mixture becomes imbalanced — leading to poor performance and increased emissions.
Common Check Engine Light (CEL) / OBD-II Codes
In compliance with the EPA’s OBD-II emissions standards, all post-1996 vehicles are equipped with On-Board Diagnostics (OBD-II) systems. The following Diagnostic Trouble Codes (DTCs) are commonly associated with Fuel Injector or Fuel Trim issues.
These codes are provided as a general reference only. Always consult a certified technician and follow manufacturer and EPA guidelines for diagnostics, sensor replacement, and ECU/PCM relearn procedures.
- P00BB – Fuel Injector Insufficient Flow – Forced Limited Power
- P02CC – Cylinder 1 Fuel Injector Offset Learning At Min Limit
- P02CD – Cylinder 1 Fuel Injector Offset Learning At Max Limit
- P02CE – Cylinder 2 Fuel Injector Offset Learning At Min Limit
- P02CF – Cylinder 2 Fuel Injector Offset Learning At Max Limit
- P02D0 – Cylinder 3 Fuel Injector Offset Learning At Min Limit
- P02D1 – Cylinder 3 Fuel Injector Offset Learning At Max Limit
- P02D2 – Cylinder 4 Fuel Injector Offset Learning At Min Limit
- P02D3 – Cylinder 4 Fuel Injector Offset Learning At Max Limit
- P02D4 – Cylinder 5 Fuel Injector Offset Learning At Min Limit
- P02D5 – Cylinder 5 Fuel Injector Offset Learning At Max Limit
- P02D6 – Cylinder 6 Fuel Injector Offset Learning At Min Limit
- P02D7 – Cylinder 6 Fuel Injector Offset Learning At Max Limit
- P02D8 – Cylinder 7 Fuel Injector Offset Learning At Min Limit
- P02D9 – Cylinder 7 Fuel Injector Offset Learning At Max Limit
- P02DA – Cylinder 8 Fuel Injector Offset Learning At Min Limit
- P02DB – Cylinder 8 Fuel Injector Offset Learning At Max Limit
- P02DC – Cylinder 9 Fuel Injector Offset Learning At Min Limit
- P02DD – Cylinder 9 Fuel Injector Offset Learning At Max Limit
- P02DE – Cylinder 10 Fuel Injector Offset Learning At Min Limit
- P02DF – Cylinder 10 Fuel Injector Offset Learning At Max Limit
- P0611 – Fuel Injector Control Module Performance
- P0612 – Fuel Injector Control Module Relay Control
- P062B – Internal Control Module Fuel Injector Control Performance
- P062D – Fuel Injector Driver Circuit Performance
- P062E – Fuel Injector Driver Circuit Performance
- P2146 – Fuel Injector Group “A” Supply Voltage Circuit/Open
- P2147 – Fuel Injector Group “A” Supply Voltage Circuit Low
- P2148 – Fuel Injector Group “A” Supply Voltage Circuit High
- P2149 – Fuel Injector Group “B” Supply Voltage Circuit/Open
- P2150 – Fuel Injector Group “B” Supply Voltage Circuit Low
- P2151 – Fuel Injector Group “B” Supply Voltage Circuit High
- P2152 – Fuel Injector Group “C” Supply Voltage Circuit/Open
- P2153 – Fuel Injector Group “C” Supply Voltage Circuit Low
- P2154 – Fuel Injector Group “C” Supply Voltage Circuit High
- P2155 – Fuel Injector Group “D” Supply Voltage Circuit/Open
- P2156 – Fuel Injector Group “D” Supply Voltage Circuit Low
- P2157 – Fuel Injector Group “D” Supply Voltage Circuit High
- P216A – Fuel Injector Group “E” Supply Voltage Circuit/Open
- P216B – Fuel Injector Group “E” Supply Voltage Circuit Low
- P216C – Fuel Injector Group “E” Supply Voltage Circuit High
- P216D – Fuel Injector Group “F” Supply Voltage Circuit/Open
- P216E – Fuel Injector Group “F” Supply Voltage Circuit Low
- P216F – Fuel Injector Group “F” Supply Voltage Circuit High
- P217A – Fuel Injector Group “G” Supply Voltage Circuit/Open
- P217B – Fuel Injector Group “G” Supply Voltage Circuit Low
- P217C – Fuel Injector Group “G” Supply Voltage Circuit High
- P217D – Fuel Injector Group “H” Supply Voltage Circuit/Open
- P217E – Fuel Injector Group “H” Supply Voltage Circuit Low
- P217F – Fuel Injector Group “H” Supply Voltage Circuit High
- P268A – Fuel Injector Calibration not Learned/Programmed
- U0105 – Lost Communication With Fuel Injector Control Module
- U0306 – Software Incompatibility With Fuel Injector Control Module
- U0406 – Invalid Data Received From Fuel Injector Control Module
- P0171 – System Too Lean
- P0174 – System Too Lean
- P2096 – Post Catalyst Fuel Trim System Too Lean
- P2098 – Post Catalyst Fuel Trim System Too Lean
- P2177 – System Too Lean Off Idle
- P2179 – System Too Lean Off Idle
- P2187 – System Too Lean at Idle
- P2189 – System Too Lean at Idle
- P2191 – System Too Lean at Higher Load
- P2193 – System Too Lean at Higher Load
- P0172 – System Too Rich
- P0175 – System Too Rich
- P2097 – Post Catalyst Fuel Trim System Too Rich
- P2099 – Post Catalyst Fuel Trim System Too Rich
- P2178 – System Too Rich Off Idle
- P2180 – System Too Rich Off Idle
- P2188 – System Too Rich at Idle
- P2190 – System Too Rich at Idle
- P2192 – System Too Rich at Higher Load
- P2194 – System Too Rich at Higher Load
- P0170 – Fuel Trim
- P0173 – Fuel Trim
- P029A Cylinder 1 – Fuel Trim at Max Limit
- P029B Cylinder 1 – Fuel Trim at Min Limit
- P029E Cylinder 2 – Fuel Trim at Max Limit
- P029F Cylinder 2 – Fuel Trim at Min Limit
- P02A2 Cylinder 3 – Fuel Trim at Max Limit
- P02A3 Cylinder 3 – Fuel Trim at Min Limit
- P02A6 Cylinder 4 – Fuel Trim at Max Limit
- P02A7 Cylinder 4 – Fuel Trim at Min Limit
- P02AA Cylinder 5 – Fuel Trim at Max Limit
- P02AB Cylinder 5 – Fuel Trim at Min Limit
- P02AE Cylinder 6 – Fuel Trim at Max Limit
- P02AF Cylinder 6 – Fuel Trim at Min Limit
- P02B2 Cylinder 7 – Fuel Trim at Max Limit
- P02B3 Cylinder 7 – Fuel Trim at Min Limit
- P02B6 Cylinder 8 – Fuel Trim at Max Limit
- P02B7 Cylinder 8 – Fuel Trim at Min Limit
- P02BA Cylinder 9 – Fuel Trim at Max Limit
- P02BB Cylinder 9 – Fuel Trim at Min Limit
- P02BE Cylinder 10 – Fuel Trim at Max Limit
- P02BF Cylinder 10 – Fuel Trim at Min Limit
- P02C2 Cylinder 11 – Fuel Trim at Max Limit
- P02C3 Cylinder 11 – Fuel Trim at Min Limit
- P02C6 Cylinder 12 – Fuel Trim at Max Limit
- P02C7 Cylinder 12 – Fuel Trim at Min Limit