Sputtering Kia Sephia 2001 (51,000, has been a great winter car)

I got the ultimate vague message in the world with the check engine light blinking on my way to the airport to get to a business meeting. 30 minutes to go, I decided I’m half way there, might as well try to make it. I did. Here are the symptoms: 1) Sputtering at just about any speed, but noticed it more on the uphills. 2) Segui to the next topic, loss of power. 3) Gasy smell from the exhaust (rich?). 4)Ideling is sometimes rough like it’s going to stall.

I brought it to the shop at Midas, and they said they ID’d it to the third cylinder. They said they traded plugs and it still had the issue. I asked if they could change the 02 sensor, roll the dice and hope. But I was told there were two O2 sensors on this car, Upstream and Downstream. To replace both was $700+ to do this.

I said replace the upstream.

It’s still not running correctly after $300.

Maybe I failed on the red/black, sort of 50/50 roulette wheel, but it’s still not working correctly.

Since they changes the plugs in the third cylinder, and had the same issue, should I get the second O2 Sensor changed? Or should I ask for a sparkplug change/fuel injection cleaning. I think it’s the first part, The other O2. That’s another $400.

Does anyone have an idea what I should spend my money on, besides a ne winter car?

First thing I would do is quit throwing parts at it hoping it will fix the problem. Take your car to a good independent repair shop and find out what is wrong.

Do you still have the Check Engine Light (CEL) on? If so get the codes pulled at one of the local car parts stores that pulls these codes for free and post the code number here, not just the description. I think then someone here might be able to help you

I thought that Midas would be able to determine the code. Not. They did mix plugs (plug3) where they thought the computer said the issue was, but it still showed as an error even with a “good” plug. So it didn’t seem like the fuels injectors.
This car has two O2 sensors. The other costs $400 to replace.

The bottom line is that Midas said to go to the dealer (this was a used car and no dealers are near) because they couldn’t figure out the code. Will Autozone do this for free?

Yes Autozone will pull these codes for free. Again post the code number here, not just the description.

Changing sparkplugs out will not check to see if your fuel injectors are working. Your injector could be plugged or the wiring could be bad or the injector it self could be bad.

You need to spend money with someone who knows what they’re doing rather than throwing darts.

An O2 sensor, pre or post converter, is not going to pick on one cylinder and play favorites with the rest. A faulty O2 will affect all cylinders and is not likely to affect your car to this degree at all.

This car should use the coil-on-plug setup and often a misfiring spark plug will knock out the coil.
A spark plug starts misfiring and you continued to drive the vehicle with a flashing CEL. This means that the spark from the coil can’t get through the plug so it’s going to go somewhere. That usually means burning its way through the boot and it does not take much of this to roast the coil.
Try changing the coil on that cylinder and see what happens.

The trouble code (itself) caused them difficulty? It may have been what’s called an enhanced code, which is one that’s set up by KIA. It would seem that the code would be P0303; which means “misfire of #3 cylinder”. This is usually caused by #3 fuel injector, or spark, or vacuum leak. I think they may have swapped #3 (ignition) coil-on-plug with another (say, #2). That was ok; but, then, they ran out of ideas. That’s why you need an independent shop which has further ideas. You don’t need a Kia dealer.