Aight I have my header install...

[yudalicious]

what car are we talking about here?
I'd listen to Big J, just from quickly perusing this thread, no one knows wtf they're talking about except him.

On your header/exhaust, it goes
o2 sensor-->cat-->o2 sensor, I'm assuming your header replaced the cat, so it's just o2 sensor------->o2 sensor, tripping CEL. Resetting (via ECU, nissan handheld unit thing, battery, etc) doesn't help, it'll come on soon again. You can either buy another cat and put it on somewhere between the 2 o2 sensors, or get a O2 signal simulator, or try the anti fouler idea that big J said.

[~The_Duke~]

what car are we talking about here?
I'd listen to Big J, just from quickly perusing this thread, no one knows wtf they're talking about except him.

On your header/exhaust, it goes
o2 sensor-->cat-->o2 sensor, I'm assuming your header replaced the cat, so it's just o2 sensor------->o2 sensor, tripping CEL. Resetting (via ECU, nissan handheld unit thing, battery, etc) doesn't help, it'll come on soon again. You can either buy another cat and put it on somewhere between the 2 o2 sensors, or get a O2 signal simulator, or try the anti fouler idea that big J said.

I am attempting to know what I am talking about...lol

The car in question is an 05 Sentra SE-R Spec V which has 2 cats stock, one in the header and one in the exhaust. When I took the first cat out it tripped the SES light (check engine light) with a your cats are not working all the way code (cas I took the stock header\1st cat out)

Ya I found that anti fouler trick a couple other car forums so he is the only one with this idea and should work like a charm. Cas I am not buying another cat lol.

It will make sense for the light to come on again since the problem that it is trying to tell you about is still there.

[yudalicious]

I am attempting to know what I am talking about...lol

The car in question is an 05 Sentra SE-R Spec V which has 2 cats stock, one in the header and one in the exhaust. When I took the first cat out it tripped the SES light (check engine light) with a your cats are not working all the way code (cas I took the stock header\1st cat out)

Ya I found that anti fouler trick a couple other car forums so he is the only one with this idea and should work like a charm. Cas I am not buying another cat lol.

It will make sense for the light to come on again since the problem that it is trying to tell you about is still there.

Yup. The KA24 has 2 cats as well in the same locations. Its well documented the 2nd one isnt even a fully functional 3way cat lol. I've also heard the o2 sim idea to work pretty well, I might try that next time.