OBX header

[WhiteGalant]

OK I have a 2003 ES 2.4 4cyl I believe its the federal spec not sure how to tell, has 2 o2 sensors one on the header directly out of the engine and a second one right after the cat thats built into the header than of course another cat right after that. wonderin what header to go with and would also like a new downpipe cause the flexpipe on the stock one is about to go.
wonderin what the best one to go with would be.

[injen4g63]

there are very good posts already on this subject. search and u should find them very easily :smt001

[badmitsu]

https://www.thegalantcenter.org/viewtopic.php?t=59444