Burnout666

I was told by someone that an aftermarket cat, like a Car Sound, would mess up the A/F readings and you would have to reset the ECU or get proper 02 sensors to handle the free flow cat. Is this BS or true? Ive never heard of a cat causing that much of an issue in the past on other peoples cars. dunno.gif

Stocker

Consider the source. If you heard it from someone who is known to be full of sh*t and has an opinion on every topic (regardless of knowledge) nevermind whatever they say.

A properly designed cat will be fine in a compatible application. If you just pick whatever cat and put it on the wrong car, it may (MAY) cause problems.

faithofadragon

So I guess Ignore this guy

tanc

Wideband or stock post cat 02?

Either way, it wont' effect anything. But the wideband goes before the cat tongue.gif

DTN

The 2nd o2 monitors catalytic efficiency. It the cat is not efficient enough, you will throw a code.


Oddly in our cars, that code IS bank 1 o2 sensor instead of cat reduced efficiency.


So... Your friend is right, for a hyundai ecu, but just plain wrong in concept.