EGR A Control Circuit Range/Performance
What it means
P0404 means the exhaust gas recirculation (EGR) valve isn't performing within the expected range — the ECM commands a position but the valve's actual position or feedback doesn't match. The usual culprit is carbon buildup gumming up the valve so it sticks or responds sluggishly. The engine keeps running, but you may notice a rough idle or hesitation, and it will fail an emissions test until the EGR system works properly.
Can I keep driving? Usually safe to drive — the engine runs, though a stuck EGR valve can cause rough idle or hesitation; get it cleaned or checked before an emissions test.
Common symptoms
What you'll notice
- Check-engine light on
- Rough idle or occasional stalling (valve stuck open)
- Hesitation, pinging, or reduced performance under load
- Failed emissions test
Common causes
Most likely first
- Carbon-clogged EGR valve sticking or not tracking commands — most commonLikely
- Faulty EGR valve or its position sensorCommon
- Wiring or connector fault in the EGR control circuitCommon
- Vacuum/electrical control problem, or rarely the ECMLess often
How to diagnose & fix
Work through it in order
- Scan the live EGR position/feedback data and command the valve to see if actual position matches.
- Remove and inspect the EGR valve for carbon buildup; clean the valve and passages — a very common fix.
- Check the EGR control wiring and connector for damage or corrosion.
- Replace the EGR valve or position sensor if it won't track commands, then clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0404?+
Can I just clear P0404?+
Related codes
Often seen with P0404
Read & clear P0404 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.