I just got a set of OBX headers off of EBay, and had my mechanic do the install. They put them on, but said there isn't a bung for one of the O2 sensors. What I want to know, is that O2 sensor really that important? Car will drive fine without it, its just for emissions right? I know CEL will go off, but will it cause engine misfire?

Is there anyway to get around having to weld in a new bung for the O2 Sensor?

Thanks for the help

the second O2 sensor needs to be put in after the catalytic converter by extending the O2 wires. purchase a high-flow cat with O2 bung already in it, or put a bung if you already have a cat installed

im currently running both o2 sensors but no cat and my light came on and engine ran weird for a few days, but then the light cut off by itself and car is running ok agin.

only downside is that everyone once in awhile the car will idle just a lil funny but if u give gas it goes back to normal. i'm assuming this just comes from the sensors trying to read that the engine is running rich.

BTW i drove my car for 2 days with NO o2 sensors because i was a dumb ass and forgot to hook them back up. didnt notice till i was looking at header the next time.

Well you'll need for emissions in RI, car will run not as well with a CEL as well.

Us midwestern states don't have emissions checks though, so he doesn't have to worry.

even though he may or may not have an emission check...why would you not want to have the o2 sensors in? espically if your car is throwing CEL's and acting funny...

you could go to an exhaust shop and have them weld you a o2 bung on it and get a cat convert with the o2 sensor bung in it and that will fix this situation...

Live in RI, and I can pass inspections no problem, got friends ;-)

I'm just worried about performance. So basicallly, I need to either weld a bung onto the headers, or get a new cat with bung pre-installed? Thanks guys

why don't you spend a few bucks, so that you don't have to worry about your "performance"

Also, install a cat, so that you and people around your car breath filtered air = less chance to get some bad disease like cancer.

Removing a cat doesn't make your car go superfast. Maybe a few hp at the crank which you won't even feel.

^^+1

<div class='quotetop'>QUOTE (Caj Darkmoon @ Jan 18 2007, 04:23 PM) <{POST_SNAPBACK}></div><div class='quotemain'>Us midwestern states don't have emissions checks though, so he doesn't have to worry.</div>

lmao.gif Didn't know RI was midwestern. wink1.gif

You have one o2 sensor bung at the moment, which goes to your first o2 sensor. Your second o2 will need a bung somewhere on the rear end of the cat or after it.

Alright, I am confused now. Had header's put on, only change. Still have cat on there, didn't take it off. Mechanic said one of the O2 sensors isn't in. I am not sure which it is, the first or second, I think hamhead is right though, and its the second one, but I'm not 100% sure cause haven't gotten car back. I thought installing the header's still left one of the Cat's on there?

Also, as to filtered air and such, if I actually cared about my lungs, or the lungs of people around me, I'd quit smoking. I did not remove Cat to try and get more performance, I replaced the stock exhaust manifold cause its a giant, clunky, cast-iron monster.

Thanks for all the help guys.