I have a 97 Accord EX. I just bought a new header and test pipe to go into a 2.5" exhaust. The new header has 2 O2 sensors in it. One in the header pipe coming off the block and one in the downpipe. Anyway today i got under the car to begin the install and i found that with the stock system there was an O2 sensor both before and after the cat.
With the new test pipe there is not hole in the pipe to insert an O2 sensor back into the system. Can i just drill another hold, weld in another nut to screw the sensor into and put a new place in the exhaust for the sensor? Or am i screwed out of using a test pipe?

Thoughts/mod threads?

 

You get your header and test pipe from ebay? Sounds like you have one of the many problems that can arise from an ebay header or test pipe.

It is typical for the O2 sensor holes to be off or be non existent. Just get O2 bungs for where the stock O2 sensors will hook up to and get bung plugs for the holes on the new header that you will not be using. You can get them at most auto parts stores.

If you can cut and weld these pieces in yourself, then you should be set. Otherwise, your local exhaust shop would be glad to help you I'm sure.

 

Don't take this personally, but you need to do some research before you start buying parts. I am sure the listing in the auction stated there is no hole for an o2 sensor and the picture would clearly show it.

Second, an exhaust shop who holds their operating license in any sort of regard will refuse to work on your car if you remove the cat.

Even if you drill a hole in the test pipe, the o2 sensor is going to give you a CEL because your emissions are going to be through the roof. Personally, I would hook up the manifold o2 sensor like normal, then use two spark plug defoulers and screw them into the second hole @ the bottome of the header and then plug your o2 sensor into that and hopefully it will trick it. You will obviously need to extend your o2 sensor wires.

However, there are other ways. Good luck and keep us updated.

 

From his post he said that it has holes, they just are not in the proper place.

Besides, most sellers that sell the cheap stuff DO NOT specify and just have a generic header picture and just say it will fit your car. They don't say how well, but that it will. Thats why you have to be careful with ebay, but thats another topic.

As for the exhaust shops... its usually not that hard to find one that will work on your car if you deleted your cat (my experience at least). Helps if you know the people there too.