A tune will turn off the code for the rear plug.

Sent from another garage.

 

Do you require to have the rear O2 sensor activated for emissions testing?

 

Not at this time.

 

Well I personally run a Vibrant j-pipe defouler with the small insert. I haven't thrown any codes and it has required no additional tuning. But you can absolutely have your tuner turn the DTC off as previously mentioned.

 

I second the vibrant j style defouler. However, with a catted down pipe, your odds of getting a CEL are slim. I'm on an MBRP catted pipe, 20k miles later, and no CEL. The first few thousand miles were without an AP and still no CEL. If a Cobb OTS, Stratified old v7 tune, MonsterX tune turns off the CEL, I couldn't tell you; but I definitely never asked for them to do so.

 

I had a 100-cell catted DP and never threw a code so you should be just fine. This was even before being tuned so nobody had touched the CPU and the sensor was showing "ready" status.

If you still want to get a defouler, I third the Vibrant J-style defouler - I currently have that with a catless DP and no issues with a CEL or passing emissions.

 

I've installed defoulers on catted DP's due to throwing codes. It does happen.

 

Vibrant J style with no restrictor, Thermal catted downpipe, stock tune.

I knew of the possibility of a p0420 going into it, so i installed the J fouler as a preventative measure.

 

Funny thing about the vibrant J, it's designed to use a restrictor, not using one causes some funky flow issues from the internal machined lip that holds the insert. Took me a while to fine tune one of my setups a bit ago, and the largest insert outflows the "No insert" config. Switching to a Denso Rear O2 from a Bosch/OEM gives you different sampling hole configuration, which has worked much better for me. I used to eat up Rear O2's.

Lots of options.

 

I ran the thermal catted DP that TurboGT now has I used the vibrant J defouler and middle restricter piece. I switched it over to my catted downpipe and just passed an emissions inspection yesterday!

 

@Duece McCracken the thing is this model, vibrant part number 11620 doesn't use inserts. I found this out on accident (meant to buy the one with inserts). I didn't feel like returning it so I used it.

I also remember you mentioning the Denso sensor somewhere else, so thats what i bought to install at the same time.

 

Ohhhhh, makes more sense. Yeah I guinea pigged a lot of setups! More to come too. I'm swapping DP's and rear dp mounts. Lmao

 

Thank you, everyone!

 

J shaped one like everyone else has. Zero emissions issues in PA. Tech doesn't see it cause of the bottom cover, and he's a friend so it's not a big deal.

 

I actually just bought a catted downpipe from a forum member and will be swapping out my catless DP for it. Previous owner said he had a tune to keep it from throwing a code. But I switched it from the tune he had to stage 2 and now stage 0. Still no code so far. I'll see what happens when I run the catted DP. I need to pass emissions, so I will check back once I have it installed.

 

That’s not the first time I’ve heard of that happening, you’ll likely throw a code eventually, you have to complete a drive cycle for that monitor to set ready or throw the code. If you don’t it will never set and stay not ready.

 

@TurboGT

J Style defouler w/ Restrictor Fittings for adjustable flow

IN STOCK Vibrant Style defouler "J" Style T304 SS (M18 x 1.5 thread) 1 pc. Includes Restrictor Fitting w/ Adjustable Flow Inserts WARNING - FOR CLOSED COURSE COMPETITION USE ONLY. NOT INTENDED FOR STREET USE. THE SALE, USE, OR INSTALLATION OF THIS PRODUCT MAY ALSO BE ILLEGAL NATIONWIDE UNDER THE...

whoosh-motorsports.myshopify.com

is this the correct defouler to get rid of that P0420 code? (with inserts)

 

That will work


Sent from my iPhone using Tapatalk

 

Might be a rookie question, but what direction should the J face? Toward the rear or the front?

 

Doesn't matter, but mine is pointed forward.

 

Thanks Coach!

 

Defouler end should point upstream. Gonna do mine shortly. Anyone know which size insert would work best for a Mountune 200 cell catted DP? I'm guessing the middle one.

 

I'm using the middle size on a cat-less down pipe; no codes.

 

Are you having a code with that Mountune 200 downpipe?

 

Yes, but only after I went to Cobb Stage 1. 99% sure the car was on stock software and it never threw a CEL prior. Code is P0420. Odd.

Check in on my most recent OP in a few days as I should have the defouler installed. It's supposed to arrive tomorrow, so I'll install that this weekend provided I have the time. Also should receive a Depo 3.5" intercooler tomorrow, so if you're interested in that product I'll probably do an install and review post soon. Expect a Stratified Stage 3 tune review as well within a month along with some logged 0-60 times as my buddy has a Racebox. Thus far I've managed a 5.89 on damp tarmac

 

Gonna try to install the defouler today along with my FMIC. Anyone know if there are preferred torque specs for the defouler/O2 sensor? Don't want it jiggling loose. I plan on using the smallest restrictor as there's no downside and I don't want to risk having to do it again. Wouldn't be fun. Could I use blue Loctite 242?

 

@CryMeARiver , you're thinking about it the wrong way man. Anti-seize, not a thread sealant. The metal will expand once hot (downpipe will get extremely hot!) & pretty much bind the threads much tighter. You may have a need to remove the sensor down the line 😉

I don't know what the perfect torque spec is, but the classic German method of "goowd ant tiight" with a decent wrench hasn't failed me yet. Definitely don't over torque, so a wrist break method is advised (unless of course you dig up proper torque specs for the compatible threading).

 

I would try the middle one before the smallest/most restrictive one since the smallest is probably more for a catless dp and definitely use some anti-seize. I believe some even get a spare O2 sensor just in case it breaks.

 

Gonna install it by this Sunday as I was cut for time this weekend. I'll try the middle of the three restrictors. I'll make sure to use anti-seize; got a preferred brand?

 

How fortuitous, I was just now looking for info on the defouler!

 

dont get anti seize on the sensors end, just a dab on the threads!

 

Yes I intend to use it on the defouler/DP bung end.

 

There is a procedure for getting emissions readiness drive cycle reset quickly.

How to Complete Ford Focus Drive Cycle?

 

Doing the install for the defouler rn and Mountune placed the bung for the downstream O2 sensor in a spot where its obscured by chassis bracing. Annoying.

 

Got it out! Gonna wipe off the threads wipe some alcohol prep pads and get the defouler in. I didn't need to take off the hard pipe--although I tried as you can see. Thankfully I have long arms and strong hands. That sucked. Breaking the torque actually wasn't difficult at all, however.