Honda Repair: hx o2 sensors, oxygen sensors, o2 sensors

Question
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Followup To
Question -
I own a 1998 civic hx. I recently put an aftermarket intake on it and have enjoyed the extra horsepower however it is currently having some problems with on of the o2 sensors, I believe it said right bank and something about the vtec. I have no clue where the sensor might be or how to repair it. please help, thank you.
Answer -
Nate,

I need some more specific information on your code. It could not have said right bank, your car is a 4 cylinder. It would say right bank if you had a six cylinder, but you don't. Also if it said something about vtec, that is a totally different code. Did you have 2 codes?
Find out exactly what it said, and I can help you. Otherwise, I can sit here and type all night, guessing what the code is, and leading  you down the wrong path.
Thanks.

Thank you so freaking much! you have really helped. I will take this info to the guy who did the test tomorrow.  for now mabye you could just tell me where they are and how many I have. Also is this a common problem?

Answer
Nate,

You have 2 oxygen sensors. The first one is in the exhaust manifold. The second one is in the Cat. converter.
Sometimes they do go bad. One thing you should check first is the exhaust manifold. They crack a lot right between the 2 and 3 cylinders. Remove the heat shield and check it. That in itself can cause you to get an oxygen sensor code.
Good luck.