P1422 Port Air Relief Valve Circuit
The P1422 code indicates that the powertrain control module (PCM) has detected a fault in the control circuit of the port air relief valve, part of the secondary air injection (AIR) system. This valve regulates air pressure directed into the exhaust manifold during cold starts to reduce emissions. The fault is triggered when the PCM senses an out-of-range voltage—such as an open circuit, short to ground, or short to battery—on the valve's control circuit during self-test or operation.
01. Most Common Causes
- Faulty port air relief valve (internal failure)
- Short to ground, short to battery, or open circuit in the control wiring
- Damaged, corroded, or loose connector terminals at the valve
- Blown fuse in the valve power circuit or AIR relay
- Faulty PCM (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Possible increased emissions or failed emissions test
03. Step-by-Step Diagnosis
Scan for codes and verify P1422 is present; check for other related codes.
Inspect the port air relief valve connector and wiring for damage, corrosion, or loose terminals.
Test the valve's resistance and compare to manufacturer specifications.
Check for blown fuses in the AIR system circuit.
If wiring and valve are okay, test the control circuit voltage at the PCM connector to rule out a PCM fault.
1. Frequently Asked Questions
Is it safe to drive?▼
Yes, it is generally safe to drive with this code, but you may notice increased emissions and the Check Engine Light will stay on. It's best to repair it soon to avoid failing an emissions test.
How much does it cost to fix?▼
Repair costs typically range from $150 to $400, depending on whether the valve itself needs replacement or if it's just a wiring or fuse issue.