- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
ECU controls the EGR system. Check for vacuum to the valve with the engine running. There should be no vacuum. If you have vacuum disconnect the electrical to the vacuum control solenoid and see if the vacuum goes away. If it does you have a command or wiring problem and will need to trace the signal wire back to the ECU.
that does not mean that the egr is bad maybe its solenoid a electric control or vacuum hose controlling the egr, or an exhaust pipe connect it to it. that code means that egr for some reason is not working the way have to work.
just because the check engine light is back on, it doesn't necessarily mean it is for the same problem. it could be, but would need to pull codes again to find out what its for. literally hundreds of different codes could turn on check engine light. also, was original code for "insufficient egr flow" or "excessive egr flow"? it makes a difference.
P0300 is misfire and p1406 is EGR. It sounds like you have a chunk of carbon stuck in the EGR valve. Remove the valve and clean the carbon from the valve, bottom side. Then install a screened gasket so it won't happen again.
U will have to run the tests for the trouble codes from both lights, they are unrelated, but chances are the CEL is the same problem, the EGR valve, in any event without the trouble codes there are far to many things to turn either light on to venture a guess, that kind of diagnosis costs allot of your money.