How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask internal88 Your Own Question
internal88
internal88, Technician
Category: Hyundai
Satisfied Customers: 2534
Experience:  Over 10 years in the Import Auto industry. Engineering background and diagnostic is my specialty.
63512786
Type Your Hyundai Question Here...
internal88 is online now
A new question is answered every 9 seconds

Changed idle air control and o2 sensors. engine idles at

Customer Question

changed idle air control and o2 sensors.
engine idles at 1800 rpm and 1000 in gear. can set idle down
Submitted: 1 year ago.
Category: Hyundai
Expert:  internal88 replied 1 year ago.

Hello, I'm Brandon - Hyundai tech.

Is the check engine light ON?

Customer: replied 1 year ago.
no I have a code P0507 and p0421. changed idle air control, can it be bad?
Expert:  internal88 replied 1 year ago.

But the P0421 is not fixed yet.

P0507 - is correct to replace the IAC.

Expert:  internal88 replied 1 year ago.

P0421 - 95% is the Catalytic Converter You will need to replace it to shut this light.

Expert:  internal88 replied 1 year ago.

5% is the exhaust manifold gasket.

It is recommend it to replace it a factory Hyundai part.

Expert:  internal88 replied 1 year ago.

I have experienced with this code in the Hyundai shop.

Expert:  internal88 replied 1 year ago.

you can check the iac by Ground the Orange/Black wire at the idle air control valve and see if the idle comes down. Check the resistance if the idle air control valve closing coil between terminals 2 and 1, to be 17 to 18.2 ohms, and the opening coil to be 15 to 16 ohms from terminal 2 to terminal 3.

Expert:  internal88 replied 1 year ago.

Please rate me positive for the prompt service, thank you!