EGR Valve Pintle Position Circuit (GM)
What does P1404 mean?
The P1404 code means the vehicle's onboard diagnostic system has detected: EGR Valve Pintle Position Circuit (GM). This is a moderate severity code.
Common Symptoms
- Check Engine Light on
- Rough idle or stalling
- Failed emissions test
- Engine hesitation under light load
- Slight engine knock under load
Probable Causes (Ranked by Likelihood)
- Carbon buildup preventing EGR valve from closing fully Very High
- Failed EGR valve pintle position sensor High
- EGR valve sticking open or closed Moderate
- Damaged wiring to EGR valve Moderate
- Clogged EGR passages in intake manifold Low
Step-by-Step Diagnostic Procedure
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Remove and clean the EGR valve -- check for carbon buildup on the pintle
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Monitor EGR pintle position data with a scan tool while commanding the valve open and closed
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Check the EGR valve connector and wiring for damage
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Inspect the EGR passages in the intake manifold for carbon clogging
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Replace the EGR valve if cleaning does not resolve the issue
Frequently Asked Questions
Can I drive with code P1404?
You can drive short distances. The EGR valve may be stuck slightly open, causing a rough idle, or stuck closed, which primarily affects emissions only.
What causes P1404 on GM?
Carbon buildup on the EGR valve pintle is the most common cause. The pintle cannot reach its expected position when coated with carbon. Cleaning the valve often resolves the code.
Can I clean the EGR valve instead of replacing it?
Yes. Removing the EGR valve and cleaning it with carburetor cleaner and a brush often works. Soak the valve to dissolve heavy carbon. If the pintle still sticks after cleaning, replacement is needed.