REDZMAN

No, because my CEL came back. P0422. I'm working on a fix for it, I've read about it and will post it when I try it out. Really though, all you can do to get rid of it and not be fooling your ECU, is to put another cat on there and hope it pulls the o2 readings low enough.

daniel_depetro

I have a cat oin my wifes car and it still has the CEL. It s a 2.5-inch high flow cat so maybe it just isn't doing a good enough job....

REDZMAN

Yup. Those codes you listed are saying exactly that, it's not cleaning enough. No worries, hopefully I'll try out my fix Friday.

radu_rd2

Could it be that the cat doesn't get enough heat to function properly? Perhaps wrapping the header and/or front pipe would help conserve more heat up to the cat?

DTN

probly not... my stock cat works just fine and throws no codes. I extended the wires rather then just pulling them back.

REDZMAN

They get plenty hot enough, it's just that High Flow Cats have much less restriction (less catalyst in the chamber, bigger diameter), so they don't clean as well. With a high flow, you are still putting out VERY little compared to other vehicles on the roads, but it's out of the specs of the ECU, so the light comes on, some of which can throw you richer to try to heat it up more to fix the problem.

BTW, remember, we have 4 wire o2 sensors, which means they are HEATED sensors, it's not the exhaust gasses that get it up to the right heat, the sensor is self heated.

radu_rd2

I see. Any simple way to "adjust" the second o2 reading, like maybe adding a resistor or something?

DTN

hasn't really been tried. You could get a e-bay o2 sensor standoff, or you could also just cap the hole and leave the sensor in open air. Either way, you're polouting the environment more then is needed and you solve the problem with the CEL.

radu_rd2

Can we add this thread to the approved DIY listing? I've been searching for it for a while, I only now found it.