C1974 Engine Trouble Code
What is C1974?
C1974 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 Chassis (C) Trouble Code |
| System: | Chassis |
| Code: | C1974 |
C1974 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
C1974 Code Structure
Understanding what each digit means in the C1974 chassis trouble code:
| C | 1 | 9 | 7 | 4 |
|---|---|---|---|---|
| Chassis Code | Fuel And Air Metering | Injector Circuit Malfunction - Cylinders | Cylinder 10 Contribution/Balance Fault | Timing Reference High Resolution Signal A Too Many Pulses |
How to Fix C1974
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:
Disconnected, dirty, or fouled spark plugs commonly prevent proper engine operation. Replace spark plugs every season or 25 hours. Verify proper spark plug gap. If plugs are good, check ignition components: spark plug wires, coils, and ignition module.
Technical Notes:
Parts or components should not be replaced based solely on C1974 DTC. Consult your vehicle service manual for proper diagnostic procedures, possible causes, and required testing before replacement.
C1974 Description
C1974 engine trouble code is related to Timing Reference High Resolution Signal A Too Many Pulses.
Main Cause
The primary reason for C1974 OBD-II Engine Trouble Code is: Injector Circuit Malfunction - Cylinders.