o2 sensor replacment

[trig]

i've been trying to search for the answer but can't find it... can sumone tell me if it's the o2 sensor on teh downpipe or the cat that i need to replace if i'm getting crappy gas millage

thanx

 

[gvr4#1372]

Well that could be caused by a lot of things.....
To ansewer your question the O2 Sensor on the Down Pipe...(i think)

 

[ProStreetOnline]

Originally posted by gvr4#1372
To ansewer your question the O2 Sensor on the Down Pipe...(i think)

Correct. The first one (usually on the o2 housing).

 

[KRAZYKOREAN]

Techincally there are downpipes with a 02 bunge on some without..like my Apexi Downpipe..there is none...its on my 02 housing and the 2nd one is on the catback exhaust..but there are 02 eliminators its on the downpipe itsself.. but yeah the 02 is a big gas mileage contender...