[Shirley]

This past late spring (2016) we started having issues with this car loosing power when accelerating. So bad it would only go about 25- 30 mph going up a hill. We had to get on the shoulder of the highway. Talk about stresssss.... We had the codes read.... changed all coil packs, & plugs. Seemed to get better for a while........ Then here we go again. So after three months of intermittent issues, we get it to code again take it to the dealer, they say catalytic converter, we are by this time 200 miles over the 80,000 mile warranty for the converter, which the dealer wants 1400. before labor......... other shops cannot yet get the factory replacement one ........ so we go to a muffler shop 450. they install a universal about 3 weeks ago. Today the temps are up outside and here we go again! That is the one common thread it runs ok when the temps are cool outside. This is just about beyond the insane point. Because I drive an hour to work this is not a working relationship with me and this car!
Has anyone experienced this issue and what it might be?

 

[neodium]

Wow, a clogged up catalytic converter, it used to be common in the early 80's...but i haven't seen that in a long while. If it's still doing the same thing with a new one, there must be something else causing the problem.

 

[GeoSoul]

It's very important to have the shop identify why the catalytic converter failed. Failure is almost always due to another underlying problem, which if not resolved will quickly ruin a new catalytic converter.

The $1400 price is at the high end of what most places charge. If you shop around you can save almost half.

Good luck Shirley.

 

[DaveInMD]

You have hopefully eliminated back pressure as an issue, which leaves fuel and air delivery, for the mechanical part, easiest to check is the air path, look at, or replace, the air filter and the intake, there could be a mechanical obstruction. I would add fuel injector cleaner next, there is a KIA approved one. Next see if you can get a fuel delivery rate and verify the fuel pump and filter can supply it, if not remove the gas cap as a test first, if air can not enter, freely then the fuel will not flow out. My snow blower would fail under load as the fuel cap was restricted. Last and most likely the hardest to find someone to be able to verify is the engine control computer, it adjusts timing, fuel delivery through the injector as well as when the transmission, assuming an automatic, downshifts through the transmission computer, and who knows what else that could cause the symptoms.

 

[neodium]

A bad oxygen sensor, witch is near the catalytic converter could be the trouble maker. Sometimes you don't get any error code about it, even if it's bad (but not totally fried).

 

[GeekOnTheHill]

It could also be the Intake Air Temperature sensor, or possibly (but less likely) the Engine Coolant Temperature Sensor. They're both notorious for causing all manner of problems but not throwing codes when they misbehave.

The IAT is pretty easy to check with a diagnostic scanner.

 

[FLHamster]

Considering that every sensor on the engine (and, most of those have already been mentioned) must have a good ground path to the battery, and that the normal path is long and full of painted connections, the quick fix, at least for troubleshooting purposes, would be to connect a ground cable from the Engine directly to the NEG terminal on the battery.

For me that would be step ONE!
Even a battery Jumper Cable would do, for troubleshooting purposes.

Without good grounds, all other attempts at a repair are just like throwing wet spaghetti against the wall to see what sticks.

Good Luck!

 

[GeoSoul]

More than likely Shirley is a one and done poster. She (he) hasn't bothered to come back.

My dad used to call them "bad actors."

 

[jcentinc]

Wow, a clogged up catalytic converter, it used to be common in the early 80's...but i haven't seen that in a long while. If it's still doing the same thing with a new one, there must be something else causing the problem.

If it really is another converter then have a leak down test on your injectors. Also, watch your oil level. If burning a lot of oil that can plug it up also. There vare a lot of things that can cause this.