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 AZTechBrian Your Own Question
AZTechBrian, ASE Certified Technician
Category: Hyundai
Satisfied Customers: 708
Experience:  Owner
Type Your Hyundai Question Here...
AZTechBrian is online now
A new question is answered every 9 seconds

2002 sonata v6 gls, sensors not ready. keep on driving 100,

Customer Question

2002 sonata v6 gls, sensors not ready. keep on driving 100, 200 300 miles. repair shop changed 3 o2 sensors and then drove a hundred mile.... still not ready.
they ar asking if they should replace the fourth one too? is it worth the try?
emissions are perfect... but sensors not ready to do smog.
Submitted: 1 year ago.
Category: Hyundai
Expert:  AZTechBrian replied 1 year ago.

Unfortunately the monitors set by drive cycles. Not miles. Hyundai vehicles are very picky about the drive cycles. I am not sure exactly how many drive cycles it will take to get your monitors to ready status, but replacing the fourth and final oxygen sensor won't make your monitors run. Here is a pdf that might help you.

Expert:  AZTechBrian replied 1 year ago.

I wish the solution was easier. Making hyundai monitors run is pretty tricky. Under normal driving, it can take a very long time before you have performed enough drive cycles where all the specific conditions have been met. You pretty much have to actually try to make them run. I found this for you too.

• The Intake Air Temperature (IAT) should be between 14 and 122 degrees F.

• Barometric pressure should be equal to or greater than 75 kPa. • The fuel tank should be between 25 and 75% full at the start of the test. •During acceleration, keep throttle 1⁄4 to 1⁄2 open.

• During deceleration, slow to less than 15 mph at an engine speed of less than 1000 rpm without touching the brake or clutch pedal.

• During cruise, maintain a steady engine speed between 1400 and 4000 rpm.

• At idle speed, keep the throttle closed and the gear selector in the Neutral position. Remember, these are just the preliminary instructions. The actual drive cycle must conform exactly to the following instructions, or the various monitors may not run to completion.

• The drive cycle begins with a cold engine startup. The IAT must be between 32 and 85 degrees F. Engine Coolant Temperature (ECT) must be less than 127 degrees F. It may be necessary to leave the car with you overnight so it can cool down completely. The engine coolant and intake air temperatures must be within a tight range to complete all of the OBD II monitors during the drive cycle. If the IAT input is not between 32 and 86 degrees F at the beginning of the drive cycle, the EVAP monitor will not run.

• Start the engine and allow it to idle in Park for one to two minutes.

•Within the first minute and a half, accelerate at 1⁄4 to 3⁄4 throttle to 50-55 mph. Hold that speed for 2-3 minutes. Unless your shop is very close to a major expressway, it may be difficult to satisfy this step in the drive cycle.

•Decelerate to 0 mph without braking, then idle for 1-2 minutes. If you’re on an expressway, pull safely off the road during this segment.

• Accelerate to 55 mph, using 1⁄4 to 3⁄4 throttle, then hold a steady cruise for 10 to 20 minutes.

• Return to 0 mph with the engine idling in Park, then turn the ignition off.

Expert:  AZTechBrian replied 1 year ago.

Were you able to get the monitors to run?

If my answer has helped you please remember to click accept and rate. If you need further assistance let me know. you can always follow up at no charge.

Related Hyundai Questions