My exhaust manifold has a crack and i wanted to throw headers in there. Will it cause a check engine light? I heard it would cause a o2 sensor code. Any info would be helpful thanks

 

How should we know? You never listed any of your car details. Y7? OBD2? New header have provision for O2? Will removing the stock header delete the catalytic converter from the system?

C'mon.

 

If you get a decent brand header with a bung for an o2 sensor you should be fine.

Try not go the ebay route, many have complained of think steel tubes that crack.

By the way if you have a y7 motor that is a different story, I am really talking about an EX. or pre 96 depending on your car.

 

Judging by past posts he has a 2000 LX with the Y7 engine. Check out this thread for info skittle

https://honda-tech.com/forums/tech-misc-15/dc-sports-header-96-d16y7-how-prevent-cel-3022890/

 

You MUST provide all pertinent information about your car and engine. Failure to do so may result in thread closure.

Creating a thread title that summarizes your specific tech problem helps you get more responses by letting members know what specific information is needed -- Title edited.

 

sorry its y7 engine no mods i read though if put headers in them they will punch o2 code even with the o2 sensors installed.

 

The Y7 header has the cat integrated into the header...so yes, it will likely throw a code for your O2 sensors reading that too many unburned gasses remain in the exhaust after where the cat should be if you get a header without the cat.
(and that integrated cat/header is EXPENSIVE, not to mention it flows like crap)

My 2 cents:
Buy an EX header-flows/looks better
The EX header should come with a downpipe
Buy an EX cat-not too expensive, ~$100 online not including shipping
Have a muffler shop fab up a short pipe between the downpipe and the cat
The have them weld the cat to your remaining exhaust pipe
Then buy some O2 sensor wire extensions from Password: JDM or extend the wires yourself if you're good with electrical
Plug in your O2's and voila!

You just converted your exhaust to an EX style!

(or be lazy like me and just buy all the EX piping and bolt it all together XD; )
The above method is sometimes even cheaper than the Y7 cat/header depending on where you get your parts from, plus it flows better!

Good luck!