2012 Kia Cadenza Exhibiting Engine Issues and Excessive Fuel Consumption

Hey there I completely get your concerns! Had a very similar issue with my 2015 Kia Optima last year. Turned out it was damage to the cable harness. It was quite a serious issue, and without getting into all the nuts and bolts, let's just say the car wasn't its usual self. It impacted all the functions such as fuel efficiency, engine power, (and yes, the notorious black exhaust smoke), and weird idling stalling. It's like the car had its own temper tantrums! My mechanic had to spend a couple of days on it, had to replace the entire harness kit. Your suspicion about the air mass sensor might not be too far off, because the damage to the harness can cause the sensor readings to go haywire. Can't say for sure if this is exactly what's happening with your Cadenza though. I'd definitely suggest taking it to a trustworthy mechanic ASAP to get it checked. Hopefully, your ride will be back in form soon. Best of luck! Cheers!

Hey, thanks for taking the time to reply! Your experience with your Optima sounds eerily close to what I'm facing with my Cadenza. I guess that cable harness issue isn't something to scoff at, huh? Just curious, do you recall how much you had to fork over to get it all fixed? Also, have you stumbled upon any similar issues afterwards, or has it been smooth sailing since then? Cheers!

Hey! You hit the nail on the head! The damage to the cable harness was indeed a serious and pricey setback. Had to part with a solid 95€ to get it tidied up and running smooth as a whistle again. Since the mechanic had a gander under the hood, there's been a dramatic change. Specifically, the air mass sensor which was throwing a right tantrum earlier got sorted. No more issues with it since then, so I reckon they fixed it up properly. So yeah, it's been pretty much smooth sailing after that. Been driving like a dream again. So, I'd reckon giving your Cadenza a thorough once-over at a reliable mechanic's is worth a shot. Hopefully, they can help you figure out what's going on. Best of luck with it! Cheers!

Hey, 95€, huh? Yeah, hate to see it, but if it sorts out all these headache-inducing problems, then I suppose it's not too bad. Been quite an ordeal, to tell ya the truth. Well, I'm definitely relieved to know that your Optima's been smooth sailing since the fixing. That gives me a bit of hope for my old Cadenza too. Guess it's time to stop beating around the bush and finally get this thing checked out by a trusty mechanic. Will try to update you about how it goes. Really appreciate your words. They've been a massive help! Cheers!