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Ask Amedee Your Own Question
Amedee, Hyundai Technician
Category: Hyundai
Satisfied Customers: 26032
Experience:  ASE Technician advanced level specialist. Wisconsin certified emissions state inspector
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Thank you so much and I will get back to you tomorrow with

Customer Question

Thank you so much and I will get back to you tomorrow with the code. Have a good one!
Submitted: 6 years ago.
Category: Hyundai
Expert:  Amedee replied 6 years ago.
Sounds good! You too!

I will be looking forward to your reply!

Edited by AMEDEE on 10/1/2010 at 2:36 AM EST
Customer: replied 6 years ago.
Hello, again! I have found out the codes for my Sonata. For some of these codes, the part has been replaced previously, the 2 knock sensors and EGR valve. Maybe old codes. But here is what is reading: p0325, p0401,p0300 for cylinder misfires. Thanks so much and I look forward to hearing from you!
Expert:  Amedee replied 6 years ago.

Sorry for the delay!

Ok... P0325 is just a knock sensor code. THis should not cause your engine to run rough. However if you want to fix this code, it is either a bad knock sensor or wiring issue. Be sure ot check over all of the wiring to and from the sensor. If all checks out good, replace the knock sensor.

The P0401 is an EGR valve code. THis can be caused by several things.

Bad EGR valve
Plugged passages
EGR solenoid

With the key on check for battery voltage at the Pink wire, ground the Light Blue wire and verify that it holds vacuum. Test the EGR solenoid several times to see if it mechanically sticks or doesn't operate after it heats up. Apply 3-5 inches of vacuum to the EGR valve at idle and determine if it stalls the engine, if not the EGR passage may be restricted. If applying this small amount of vacuum to the EGR valve does cause the engine to stall at idle, test the vacuum control valve to determine if it is outputting the proper amount of vacuum. There should be manifold vacuum to the valve and it should output about 7 inches of vacuum. If not the vacuum control valve may be faulty. Test the operation of the EGR solenoid, if the solenoid is energized at idle it should cause vacuum to be applied to the EGR valve and should stall the engine.

P0300 is a random cylinder misfire. We covered a lot last time so I believe you are aware of what this code all means. If the tune up parts are good and the crankshaft position sensor is ok, then your mass air flow sensor could be bad causing this problem or maybe your EGR valve is sticking open causing this code as well. The mass air flow sensors are really common on these vehicles so you might want to check into that further.
Amedee and 4 other Hyundai Specialists are ready to help you
Customer: replied 6 years ago.
Okay, thank you so much for your expertise. I'm going to start with the crank shaft position sensor and then maybe the mass air flow if needed.
Expert:  Amedee replied 6 years ago.
Sounds good!

Good luck!

If my memory serves me correctly, the crank sensor can be a pain to put in... If you do it yourself, just be sure to have plenty of time to put the new sensor in correctly.