I have a honda civic si 2008 I change my headers and catalytic converter for after marker headers and it runs fine but the engine light came on wat can I do to fix that problem

 

I'm no expert, but your ECU might require a software upgrade (because of o2 sensor).

 

The engine light is likely your secondary o2 sensor. You will need to get something like a defouler to try and trick the system but they don't always work and it's not the ideal solution!

The best solution and the one you should of done before purchasing your header was to get Hondata Flashpro so you can tune your car properly. With the Flashpro you are able to disable the o2 sensor which will clear the engine code. Not only will it do that but you can tune your car correctly so you can maximize the power it is making!

I got mine at the same time as I bought my intake and honestly I should of got it when I bought the car. It's a night and day difference!

 

The only reason I change was bc I heat a man hole and destroy my catalytic and where I can fine the parts that I need?

 

Trust me you are better off to get the Flashpro... save up for it you won't regret it! It's the correct way of doing it.

Getting the defouler is a hit or miss! It didn't work for me on my EP3 and a few of my friends...
This is what you will need:
http://www.prostreetonline.com/x/blo...eliminator.asp

 

btw get the vibrant one as it's cheaper here is the part number#11621 or you can get the one that bends a little #11619.

 

Thanks Dave I other the first one lets see if it works if not I get the flashpro

 

Update the thread once you get it!

 

Wats the thread and I got it already do I need to get a new 02 sensor I drove the car like that like for 100 milles

 

The thread is this right here lol...

No I do not think you need to get a new o2 sensor. The sensor was actually doing it's job if it gave you a code.

Remember when you put the defouler you need to disconnect the battery for 10 minutes and then reconnect it and make the car relearn itself. I would let it idle until it's idling at around 700-800 rpms and then take it out for a drive (30 minute drive).

Then the real test will be if after all that you don't get another code!