I'm running catted kooks y pipe, you will burn the stock cats up pretty quick with a hot tune. Just an FYI. Get kooks or ARH they fit perfect and actually make power and sound good.

 

WB goes before the cats but after the Y pipe so you get a reading from both sides. Otherwise you can install 2 WB O2s (one for each side), but that gets pretty expensive.

O2s are just NPT threads. Most muffler shops sell them if you have your own welder. Or they will charge a little to install but then you screw in the sensor yourself.

I hear you, a lot of muffler shops are really sketch about anything before the cats. They will mod all you want after the cats but once they've been pinched for stuff before the cats, its almost like pulling teeth to get them to even weld in a bung before the cats.

 

Both of these statements are sort of wrong.

WB should go as close to the engine as possible. You do not have bank to bank control with the factory system, so letting it "see both banks" is pointless and just adds delay time to the reading and increases the risk of it seeing leaks. Put it right near the front o2 sensor as far forward as possible, either side is fine.

O2 senors are not NPT thread, they are M18 and use a sealing washer. Most shops will install a bung for like $20.

High ethanol fuel is good for performance, bad for mileage. Which one would you rather have?

 

Yeah the wideband instructions say to weld it 24" past the manifold flange, and that is impossible with the stock configuration. I guess once I figure out exactly what I'm doing with the exhaust I'll worry about it. Didn't consider the increased output blowing out the stock cats as is. As for the ethanol, it's only 15% ethanol mix, so seemed illogical to have such a polarized impact that the na motor did not have.

I'm keeping my eye out for some sort of discount on a arh or steel works header and y combo.

 

Yep. Oops. I made a mistake. sorry.

size: M18x1.5