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 Mike V. Your Own Question
Mike V.
Mike V., Technician
Category: Kia
Satisfied Customers: 25314
Experience:  I have 25 years experience working on cars. I am also a factory trained Subaru and Nissan Tech.
Type Your Kia Question Here...
Mike V. is online now
A new question is answered every 9 seconds

Kia Optima LX: Mike, . I have an 06 Kia

Customer Question

Hi Mike, My name is Kris. I have an 06 Kia Optima My check engine came on early spring. The car was running ok, a little sluggish when it was in a high gear and I would downshift and it would be fine. but it had started to occasionally stall. I took it to my mechanic for an oil change and a little spring love and to see why the check engine light was on. A code came on for cylinder 2 and 4. He gave my car a tune up, changed both ignition coils and replaced the cam shaft sensor. Soon after the light came on again and the car started "chugging" or misfiring. I took it back, he this is the list of what he did:1 camshaft sensor, 2 coils, 1 wire set, 1 crankshaft sensor, 1 timing belt, balance shaft belt, 1 crank shaft belt, 1 crank shaft seal, 1 balance shaft seal, 4 spark plugs....It is still misfiring and the codes for cylinder 2 and 4 are still coming on. He's flummoxed as am I . Can you help? Thank you. Oh also, it runs fine while the engine is cool, as soon as it gets hot.
Submitted: 2 years ago.
Category: Kia
Expert:  Mike V. replied 2 years ago.
Hi there,Have him pull the upstream o2 sensor and see if it runs better. It sounds to me like your catalytic converter might be plugging up. This will cause misfires because it leans out the cylinders. Especially worse when the engine is up to temp. That being said, since the misfires are consistent with the cylinders, he might also want to check and make sure the spark is good when it's up to temp and even swap the fuel injectors around to see if the problem moves to new cylinders.I think the converter could be the problem though, based on the info you are giving me, the one right off the exhaust manifold.Please let me know what more I can do to assist you with this.What happens next:Just Answer will now charge you for the full amount of your question.My goal is to provide you with 5-star service. If you cannot rate me at least 3-5 stars, we will keep working on this.Just Answer does not compensate me for my time and effort; you do with a 3-5 star rating.Follow up questions are included in your question price even after rating.
Customer: replied 2 years ago.
Hi Mike,
I visited my mechanic and he pulled the o2 sensor, it didn't change anything. He won't have time to do any other work on it until next Monday. He wanted me to elaborate on my issues and also offered you to email him direct if possible. His email***@******.***. He wanted me to tell you that the codes for cylinder 2 and 4 are consistently what comes up, which the coils sit directly on top of....these are the codes, PO302 cyl 2 misfire, PO304 cly 4 misfire, PO300 random misfire and PO342 camshaft position sensor A circuit Low Input. he has replaced the camshaft. He felt that the it was strange to suggest the converter with the misfiring. He is going to try swapping the fuel injectors next Monday. I've put about $1,500. into this already and I think my mechanic is also concerned with dumping more $ in with the converter. Any more advice would be greatly appreciated, thank you
Expert:  Mike V. replied 2 years ago.
I agree with doing nothing with the converter because if there wasn't any improvement then it's not the problem.I suggested it for 2 reasons. First, a misfire will cause a converter to melt down and plug up and there isn't any telling how long the car was missing and second, I have seen these melt because they are so close to the engine.He should use a scan tool to check the timing/cam sensor. It's possible it's off a tooth or two, this would cause a consistent cam signal code.The only thing that is a bit confusing is that it's only after the car is heated up that you are getting these misfire codes. Another reason I was thinking possible converter.have him check all the grounds for the coils, since it's both the COP that are failing or misfiring when hot it could be a ground issue, or possibly the coils themselves. If he is using aftermarket I have seen them fail and leave you chasing the same problem. I can't really email him directly so we have to do this here.
Customer: replied 2 years ago.
I am happy to rate you after my mechanic gives your advice a try on Monday. Thanks so much
Expert:  Mike V. replied 2 years ago.
Thanks, ***** ***** really appreciate it and if we don't have success let me know and we can keep working on it.
Customer: replied 2 years ago.
Expert:  Mike V. replied 2 years ago.
You're very welcome Kris