P306E Engine Trouble Code
What is P306E?
P306E 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 Powertrain (P) Trouble Code |
| System: | Powertrain |
| Code: | P306E |
P306E 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
P306E Code Structure
Understanding what each digit means in the P306E powertrain trouble code:
| P | 3 | 0 | 6 | e |
|---|---|---|---|---|
| Powertrain Code | Ignition System Or Misfire | Ambient Air Temperature Sensor Circuit Low | Cylinder 4 Contribution/Balance Fault | System Malfunction |
How to Fix P306E
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:
VSS concerns may stem from noisy input signals caused by RFI/EMI from ignition wires, charging circuits, or aftermarket equipment. Verify VSS reads 0 mph when transmission is in Park.
Technical Notes:
P306E DTC specifically relates to camshaft timing. When cam timing is over-retarded, the check-engine light illuminates and this code sets. Verify VCT solenoid operation and check for contamination.
P306E Description
P306E engine trouble code is related to System Malfunction.
Main Cause
The primary reason for P306E OBD-II Engine Trouble Code is: Ambient Air Temperature Sensor Circuit Low.