collector of my header?

This would be for a wideband O2 sensor/guage (Thats why I posted in this forum)

Is it okay to put it there? As far as the sensor goes, will get an accurate reading if it's on the collector?

I don't mind putting a hole in the header but I would mind if it screwed up the A/F reading.

 

Too close

 

If you look on AEM's website, they sell a "clamp style" O2 bung. You can put it anywhere past the collector. On the header is a bad idea. The clamp bung really works and doesnt leak. I have friends that have used them with no issues.

 

okay, good info. can you put it anywhere past the cat or does the cat really need to be replaced?

if a bung in the collector is too close, why is the factory o2 sensor there?

 

As long as you put the sensor after the collector, anywhere is ok. Drilling into an exhaust manifold usually isn't fun, especially if it's aftermarket, kinda hard to sell it if there's a hole in it. lol. I have two O2 sensors. The one is wired to my ecu/S300 and the other goes to my AEM UEGO gauge. I could have wired them together but it was easier this way.
When it comes to cats, it's kind of a legal issue. Plus it's been shown that removing the cat doesn't actually "help" unless the old one was clogged. But a high flow cat is better than a "test pipe".

 

Okay, you have the setup im shooting for with the UEGO wideband and S300. I've got the JDM type r exhaust manifold down to a 2.5" highflow cat to 2.5" exhaust. I'm in the planning stage so I'm trying to figure out when I get the UEGO, where in the exhaust I'm gonna plug the o2 sensor in at. where would i get the most accurate reading... post-cat?

 

I would recommend putting it before the cat. If you put it after the cat your reading won't be as accurate because the cat will filter out the exhaust therefore not giving you a true reading. A good cat turns all the bad stuff (unburnt fuel) into carbon dioxide.

 

There are a number of pictures of O2 bungs in Honda headers just before the collector, actually that is where 90% of them are located. The other 10% are located in the primaries. However if you are only running one, this will really only give you the AFR's for that cylinder. Use Google images and search for "Honda headers O2 Bung" and you will see where you can place it.