B0143 Engine Trouble Code
What is B0143?
B0143 indicates potential catalytic converter failure. If completely failed, your vehicle may not run properly and fuel economy will suffer significantly. Average replacement cost is $2,000–$2,140. This repair requires professional service and should not be delayed.
Code Information
| Code Type: | OBD-II Body (B) Trouble Code |
| System: | Body |
| Code: | B0143 |
B0143 Symptoms
Check Engine Light
Illuminated dashboard warning
Engine Stalling
Engine stops unexpectedly or misfires
Performance Issues
Reduced power or acceleration
Starting Problems
Difficulty starting the engine
B0143 Code Structure
Understanding what each digit means in the B0143 body trouble code:
| B | 0 | 1 | 4 | 3 |
|---|---|---|---|---|
| Body Code | Intake Valve Control Solenoid Circuit Low | Fuel Rail/System Pressure — Too High | Injection Pump Fuel Metering Control 'B' High | Exhaust Gas Recirculation Sensor B Circuit High |
How to Fix B0143
Diagnostic Steps:
The catalytic converter has oxygen sensors before and after it. When warm and in closed-loop mode, the upstream O2 sensor reading should fluctuate, while downstream should remain steady.
Repair Solution:
Power steering pressure switch monitors system operation. If pressure changes are not detected after calibrated speed transitions, this DTC sets. Verify PSP switch operation and check for circuit opens or shorts.
Technical Notes:
B0143 DTCs can be triggered by upstream issues. For example, a dirty MAF sensor may cause incorrect fuel-trim adjustments, leading oxygen sensors to report mixture problems. Address root causes first.
B0143 Description
B0143 engine trouble code is related to Exhaust Gas Recirculation Sensor B Circuit High.
Main Cause
The primary reason for B0143 OBD-II Engine Trouble Code is: Fuel Rail/System Pressure — Too High.