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Discussion Starter · #1 ·
Car is a 2013 Optima sxl 2.0L My main issue is random misfires from all cylinders (thrown as single cylinders at different times) . Got new coils, new plugs, and car idles like its perfectly fine when at operating temperature. I can drive the vehicle like normal with light throttle even up to highway speeds, but the issue starts when i throttle mid to heavily....like merging into traffic or something. Basically just about any time im not feathering the gas pedal, the car will start jerking and throw a misfire code beginning around 2500rpm and up. Im already on my 3rd engine ?‍♂(long story) with this car and my loan isn't going away anytime soon, my last guess was possibly a sensor (02 or map) but im tired of throwing money into this thing. Just to guess and be wrong again. Now i personally drive very aggressive and the last 'I guess modification ' i did was installed a blow off valve. Car ran fine for a while after constantly stomping on pedal and letting off to hear the bov then outta nowhere the issue began as i was driving highway speeds one night. Any ideas or opinions on what to do would help a mill. I should also add that it does seem like cylinder 2 runs a bit rich and this is the same cylinder that recently had a injector replaced.....thought that was the issue for a good while until, my obd scanner claimed cylinder 4 was misfiring now instead of 2, and live readings gave misfire counts for all cylinders which were slight ......like misfire count: 6-203 of 4k or something .
 

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2011 Kia Optima
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Usually a 300+ multiple cylinder misfire code is a problem not associated with the coil/plugs, but something upstream. Have you checked for any leakage in the air intake system, e.g loose clamps, intercooler leaks, catch can leak if one installed, etc?
 

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Discussion Starter · #3 ·
Thought it could be the bov so just took that out and installed the oe one. That wasnt it, checked hoses, plugs, everything was connected. Went for a test drive after putting oe bov back on and decided to give the sportmatic a try. Car accelerated as usual, stuck in the same gear unless i shifted, it actually accelerated much quicker all the way up to 6.5k red line with no issue as stated before unless i gave it heavier throttle.

Basically issue only occurs under conditions below:

-cold start, when vehicle is revving up to 2k rpms alone(running richer than usual)

And

-when giving anything more than lets say 20% throttle
 

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Yeah, that's what I was going to say... check the wastegate voltage. I believe it should be between 3.9v and 4.1v although some ppl say 4.2 You don't really get a choice of exact voltage as you can only adjust by half turns of the actuator rod.
 

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Discussion Starter · #6 ·
I did not check the wastegate but while checking tps, i kinda pushed the car so it would throw the misfire code and got a p2297 for o² sensor. Now if possible can anyone show me where it is located (pictures would help alot)? Im an amateur with basic understanding of everything haha. Looking for the bank1 sensor 1, 0² upstream. Also does the sxl use 4wire or 5wire sensor? Most likely 5 for heating i believe.? Thanks in advance.
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No clue of the O2 sensor location but the odds "it" failed are not high, was probably just triggered from an imbalance of fuel vs air due to the cylinder fault. Have you added a custom control chip? That could certainly throw off the factory fuel/air ratio settings and cause all this. If not, you may want to replace it or get a programmable one and see if helps.
 

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Discussion Starter · #8 ·
I
No clue of the O2 sensor location but the odds "it" failed are not high, was probably just triggered from an imbalance of fuel vs air due to the cylinder fault. Have you added a custom control chip? That could certainly throw off the factory fuel/air ratio settings and cause all this. If not, you may want to replace it or get a programmable one and see if helps.
Actually did have one installed but removed it a while ago. Would i need an ecu reset?
 

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I would say worth a shot. If you didn't let the system dissipate the internal capacitance between swapping modules then it could well have kept or corrupted some of the settings from both. Read this on another post to DIY reset the ECM: "disconnect the negative wire from the battery and wait aprox 1/2 hour... all charged backup capacitors will have discharged and the ECM's memory will have been erased.. The memory is stored in what is called an EPROM and the loss of power will result in erasure... An EEPROM (used in other electronics) will still have it's memory when power is re-established and may be used in newer and other cars... " Hope it helps!
 

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Discussion Starter · #10 ·
Update, oreilly sold me non turbo coils. And it took me one 4 hour trip to the dealership to figure that out, so future reference. Always go for turbo rated coils from dealership if possible $20-30 difference from auto part store.
 
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