I just received some O2 Sensors for my '99 XLT (4x4, if that makes a Dif.?) 4.0, and am wondering: Which side does my Upstream go on? I'm told (via Google) that it goes "Before the Catalytic Converter" but when they say that, are they referring to the Side faces the Block?
I know I sound stupid, but when I see stuff like this, I can't help but think of how they call the "Back" of a Semi Trailer Near the Doors, and the "Front", near the Cab. Something that has always perplexed me... So, before I crawl under this thing and working on it, I'd like to be in the Know.
Thank you for helping this Noob get a grip! ('Preciate y'all!)