i just bought a new MAC H-pipe and 2 pypes hi flow cats. the h pipe came with 4 O2 sensor holes, 2 near where the engine is and 2 further back. the cats each came with 1 O2 sensor hole on each of them so now i have 6 O2 sensor holes.

home many O2 sensors does my car even have it's a 2004 mustang v6 auto.

im sure it dosent have 6 so what do i do with the extra holes.

 

should only need 4..... 2 before the cats and 2 after the cats for a dual exhaust system

 

i know i only need 4 but i have 6 lol. so im just going to use 4 and weld shut the other 2 i think. idk

 

Why didn't you just buy a catted H pipe?

 

they dont make one. MAC discontinued it and its about the same price to build ur own so i was like cool

 

ah i see, well good luck mang.

 

you only need 4. 2 on the manifold/headers and 2 behing the cats. you can cap the other 2 holes off. I have a xtra for wideban and when I dyno it. They mmay become useful for you if you go that route.

 

will i need an O2 extention kit

 

They normally don't need extentions...barely fit. But in your case i think your just gunna have to get under it and see.