2005 Kia Sorento fuel injection

Not likely, but the fuel injection service - what exactly did they do? If it is the pressurized fuel injection service, it may signal for check engine light (possibly for system too rich) that the O2 sensors can't compensate, but it has nothing (well, remotely) to do with the catalytic converter.

Why do you think the services damaged the emission system? Do you have the check engine light? Get it scan at your local auto parts store for free, and get back with us with the code numbers and description.

Oh by the way,

Whomever you talked to at the dealership, he is only concerned about selling you 4 new O2 sensors and 2 new catalytic converters, plus installation. That is roughly $3K sales (commission ka-ching, if you ask me). While it is, remotely, possible to damage your emission system by using too much fuel injector cleaner, it is very highly unlikely.

If whatever your dealership guy said was true, than I would have to install hundreds new catalytic converters on all the vehicles that I have done fuel injection cleaning services. Let me tell you, NONE of these cars ever needed any emission parts replaced.

So, this is what I want you to do. Reset the computer thus erasing the check engine light. Any Autozone or CSK/O'Reilly will do this for free.

IF the check engine light comes back on, get it scanned at the same place you erase the code. You may have to this a couple of times to get most of the residue of the chemicals out of the system. And then, get back with us with the code numbers and description.

Get it scanned one more time, and tell us the exact code numbers you get.