Your 2022 Cadillac CT4 has developed hesitation during acceleration, and the check engine light reveals code P0441—EVAP System Incorrect Purge Flow. This code points to the emissions control system, but the connection to engine hesitation makes more sense than you might expect.
Understanding P0441
The EVAP system captures fuel vapors from the tank and routes them to the engine to be burned. The purge valve controls when these vapors enter the intake. P0441 indicates the system isn't flowing properly—either too much, too little, or at the wrong times.
How EVAP Causes Hesitation
A stuck-open purge valve continuously dumps fuel vapors into the engine. This unmetered fuel creates unpredictable mixture variations that the PCM must compensate for. The result is hesitation, stumbling, or rough running—especially during light acceleration when the extra vapors have more proportional impact.
Common Causes
Purge Valve Stuck Open
The most common cause when driveability symptoms accompany P0441. The solenoid fails in the open position, creating constant vapor flow.
Purge Valve Stuck Closed
Fails to flow when commanded. Sets code but typically doesn't cause hesitation.
Vacuum Leaks in EVAP System
Cracked hoses or loose connections create unmetered air entry.
Charcoal Canister Issues
A saturated or damaged canister affects purge characteristics.
Diagnostic Steps
- Purge valve test: With engine off, check for vacuum at purge valve—there should be none. Vacuum present indicates stuck-open.
- Fuel trim check: Large fuel trim variations may correlate with purge events.
- Visual inspection: Check all EVAP hoses for cracks and connections.
- Scan live data: Monitor purge valve commanded state versus actual behavior.
Repair Options
Purge Valve Replacement
Usually the fix when hesitation accompanies the code. Cost: $100-$250.
EVAP Hose Repair
Replace damaged hoses. Cost: $50-$150.
Canister Replacement
If saturated or damaged. Cost: $200-$500.
After Repair
Clear codes and complete a drive cycle to verify repair. EVAP codes sometimes require specific driving patterns to fully clear.