Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means there's a leak in the system that helps clean the car's exhaust. It's like having a hole in a straw when you're trying to drink a milkshake.
The P20CA code indicates a problem with the air pressure in the reductant injection system, which is part of the vehicle's emissions control system.
The reductant injection system is responsible for injecting a urea-based solution (DEF) into the exhaust stream to reduce nitrogen oxide emissions. The P20CA code is triggered when the system detects a leak in the air pressure used to inject the reductant.
• Check Engine Light is on
• Increased emissions
• Possible reduction in engine performance
• Damaged or leaking air lines
• Faulty air pressure sensor
• Defective reductant injector
Reductant: A substance used to reduce pollution in the exhaust.
DEF: Diesel Exhaust Fluid, a urea-based solution used in emissions control.
• Inspect the air lines for leaks or damage.
• Check the air pressure sensor for proper operation.
• Test the reductant injector for leaks.
• Replace damaged air lines.
• Replace faulty air pressure sensor.
• Repair or replace defective reductant injector.
• OBD-II scanner
• Pressure gauge
• Basic hand tools
$150 - $500
Moderate
• Ford F-250
• Chevrolet Silverado 2500
• Ram 2500
• Regular maintenance of the emissions system
• Check for leaks periodically
• Use high-quality DEF fluid
Emissions Control System Issue
• Don't ignore the Check Engine Light.
• Have the vehicle inspected by a professional.
• Avoid driving long distances until fixed.
Emissions-related repairs may be covered under the vehicle's emissions warranty.
This code has become more common with the increased use of DEF systems in diesel engines.
Moderate – It's important to address this issue to ensure emissions compliance and prevent further engine problems.
Ignoring emissions issues can lead to fines and increased pollution.
• Engine running at operating temperature
• Vehicle in motion
The reductant injection system is typically located near the exhaust system, under the vehicle.
Q: Can I drive with a P20CA code?
A: It's not recommended to drive for long periods with this code, as it can lead to increased emissions and potential engine damage.
Q: Will a P20CA code affect my vehicle's performance?
A: Yes, it might lead to reduced engine performance and increased emissions.
Budget · Enhanced code reader
A wired color-screen reader with readiness hotkeys, live data, code definitions, and data logging.
Good for emissions-related codes because it exposes readiness monitors and live powertrain data.
View on Amazon
Specialty · Smoke machine
Helpful for finding EVAP and vacuum leaks that are hard to see with visual inspection alone.
Helpful for tracking down EVAP and vacuum leaks that can trigger emissions faults.
View on Amazon
Specialty · O2 sensor socket
Helpful when the code points toward exhaust or oxygen-sensor work and space is tight.
Useful when the diagnosis points toward oxygen-sensor removal or replacement.
View on AmazonThese are optional diagnostic tools, not guaranteed fixes. As an Amazon Associate I earn from qualifying purchases.