owenxguo

As I understand, second o2 is for monitoring the cat. Beside the CEL, is there gonna be problem to remove it by just unplug it?

deathsled

Just the CEL

N2oExpresS2k

The front 02 is the one that controls your air/fuel. Having a cel sucks tho, then you wont kno if another problem comes up..

deibit

In a few words.. you will get an anoying light in your dashboard, your ECU will not relearn, your ECU will not use the main lambda probe to adjust the A/F ratio.. side effects are that your car will waste more fuel and "probably" will loose some power on some rpm range. Your emissions would be not optimal/ecological as well... maybe you will have some additional side effects

Your car will run like when when its cold or when it's on WOT (so in open loop) while the CEL light is on.

owenxguo

I need the bang on testpipe for wideband O2 for now, lazy of weld another one for stock sensor, so I guess I'll just unplug it til got EMS.

Thanks guys

Slows2k

If the wideband is mounted in the convertor it won't be accurate.

Kirpich

No, he said wideband is in the testpipe, he don't have a cat. OP, right?

How _do_ you install a wideband? 3rd bung? Somewhere between the cat and the first O2?

Slows2k

I don't know what he's got int he exhaust system.. Causing a permanent CEL is bad idea. You'll never know if you have a more serious problem because you've caused another.

owenxguo

Test pipe, my CEL was on because of air pump removal.

SortaRican

Excuse me if I'm wrong but CEL is only for emissions eqipment anyhow correct? Not gonna predict any kind of catastrophic failure anyhow.