2018 Kia Sorento - Catalytic converter issues

My 2015 Kia Sorento has this same problem. Front catalytic converter breaking pieces into the rear catalytic converter…May have damaged the engine

Too bad. What is your question?

2015 or 2018? Miles? The cat(s) are covered by an 8 year/80,000 mile factory warranty.


Thanks for the info, but KIA has never really been on my radar.

How would broken pieces in the catalytic converter hurt the engine? Last I checked, exhaust was a one way street…

I guess there could be some exhaust blockage issues, but still…


IIRC, this was a problem with certain Nissans (possibly Sentra?) about 10 years ago.
CC material was sometimes drawn back into the engine, with bad results.

The catalyst/manifold assy is mounted right at the exhaust ports of the cylinder head. It’s not too much of a stretch to see that debris floating around right next to an exhaust valve might make its way into the cylinder.

Fair enough. I hadn’t considered that.

Pressure and rarefaction waves can bounce back and forth in the exhaust piping.
Also, with a multi-cylinder engine, a pressure pulse from one cylinder (when the exhaust valve first opens) can find its way to another cylinder in the middle or end of its exhaust stroke and momentarily interrupt or reverse the exhaust flow.
A good exhaust system will minimize the interactions, but flow (and debris) reversal can happen under certain conditions.

Exhaust leaks downstream of an o2 sensor can result in the o2 sensor not reading the exhaust gas o2 content correctly. Outside O2 can be drawn into the exhaust and go backward a short distance, reaching the o2 sensor. .