Long tube headers and O2 simulator vs $5 option

[Adoniram]

Hello all, I just picked up a '17 limited and am wanting to add a few things like CAI and headers. TRD CAI is already on its way (thanks to the parts list available on the forum here), and now I'm onto DT long tube headers. URD sells them and says they have an O2 simulator for the O2 sensor located behind where the cats used to be. However... their site doesn't have them listed in stock, or doesn't indicate exactly which unit goes with the 17 4Runner.

Has anyone bought this? More importantly, has anyone used the $5 option with success?
http://www.toyota-4runner.org/3rd-gen-t4rs/175242-how-make-your-own-rear-o2-simulator-%245.html

That seemed to do the trick for the 3rd gen, and I'm wondering if the same is true for the 5th gen.

Thanks!

 

[wfo9]

17 4runner exact same as 2010+ 4runner/FJ.

 

[Adoniram]

Curiously, the site has these headers for 2010-2012:
https://www.urdusa.com/thy-515-ls-c-thorley-header-2010-12-fj-cruiser-4runner-4-0l-v6/

And these for 2013-2017:
https://www.urdusa.com/thy-518-ls-c-thorley-header-2013-fj-cruiser-4runner-v6-wair/

There does seem to be a discernible difference with some kind of port at the top of the newer version... if they're identical engines, what's with the extra port? The same is shown on the Doug Thorley website.

Anyway this makes me nervous about something changing in the O2 sensor department, meaning the O2 simulator from '10-12 models won't apply to '13-17 models...

 

[wfo9]

Curiously, the site has these headers for 2010-2012:
https://www.urdusa.com/thy-515-ls-c-thorley-header-2010-12-fj-cruiser-4runner-4-0l-v6/

And these for 2013-2017:
https://www.urdusa.com/thy-518-ls-c-thorley-header-2013-fj-cruiser-4runner-v6-wair/

There does seem to be a discernible difference with some kind of port at the top of the newer version... if they're identical engines, what's with the extra port? The same is shown on the Doug Thorley website.

Anyway this makes me nervous about something changing in the O2 sensor department, meaning the O2 simulator from '10-12 models won't apply to '13-17 models...

Forgot about that. Pretty much the only mechanical change (if you want to call it that) made to the 2010+ was start up air injection being added in 2013. I'm not 100%, but 95% sure the 02 sensor are the same.

 

[oljedi11950]

URD Usa

Best bet for info is Urd , my headers on 05 are perfect fit & they oem fit style ! :hungry::wow:On 11' got rid of rear Cats with urd y-pipe & didn[t need O2 sim !

 

[4RunnerAquasport]

+1 for the URD Y pipe.

 

[Adoniram]

Might do both... the vehicle is emissions exempt for 7 years in Colorado, so it's not like I'll fail a test or anything... Hopefully URD replies to my email. I'll just call next week if I don't hear back.

 

[Friggin Idiot]

Best bet for info is Urd , my headers on 05 are perfect fit & they oem fit style ! :hungry::wow:On 11' got rid of rear Cats with urd y-pipe & didn[t need O2 sim !

I believe '10+ have a pre-cat as the tail of the OEM manifold before the Y-pipe and O2 sensors. Removing those pre-cats without the O2 simulator by installing headers, the engine will throw a code and trip the CEL.

When I installed my y-pipe I couldn't seal the connection to the manifold/pre-cat because I stripped a couple of the bolts. It sounded like crap with the exhaust leak, power output suffered, and the O2 sensors threw a code triggering the CEL, TRAC and another light less than 30 miles after I started up. Had a shop replace the bolts, seal it all up, and clear the codes and it runs fine with URD Y-pipe & Mk3 Exhaust on OEM manifolds no O2 simulator.

This is the exact reason I didn't do headers yet, I'm not ready to run completely without a cat just yet as I may need to move somewhere with emissions testing. If they only test with the OBDII and not the sniffer, it should pass with the O2 simulator. But the gig is up as soon as they look under the truck and see there's no cats there at all! Last time I was in VA (Stafford Co near NorVA), they actually did a dyno run on my Subie for the test!
There are shorty headers out there which allow you to cut off the OEM pre-cats and weld them on the shorties, but the shops I got a quote from wanted another $600 to do that. Add in the cost of the shorties and that's about $1k for little gain. I might do long tube headers and a simulator down the road along with adding a cat to the mid-pipe to help the environment and pass a sniffer check. Why not move the O2 sensors to after the new mid-pipe cat? I'm pretty sure the temperature difference will cause issues. Also the required amount of extension wire and extra connectors to get them that far back could change the voltage through added resistance, not to mention be rather vulnerable to off-road hazards.

 

[oljedi11950]

2011 & no issues with y-pipe & no cats ! Did it myself in driveway thought I needed a o2 sim but nope & re-installed both o2 sensors in bungs provided on y-pipe have never thrown a code !So have xtra o2 sim if son's 05 ever expires !

 

[oljedi11950]

Yes @frigginidiot 2 above & 2 below cats , I only removed rear 2 ! On son's 05 we went with urd headers & are using their o2 sim ! Op you can go on their website & peruse all available headers they sell !

 

[Adoniram]

So I heard back from URD, and the headers are indeed different. One may fit the other but there’s something unique about the 13+ units. Probably related to that extra piece on the top.

More importantly, there is no O2 simulator for the 13+ units. They do not have a reliable way to do it, thus they don’t sell it. You will always have a CEL if you put headers on a 13+ 4Runner. Unless you know something they don’t know.

So that begs the question: has anyone put long tube headers on their 13+ and reliably avoided a CEL?

 

[oljedi11950]

This might not be what you want to do but IMO , unless you REALLY want lt headers I would start back & work fwd . Try their y-pipe & see how it feels & maybe by then you'll either have more options or won't want headers anymore ? I was the same wanted headers but did this 1st & it was enough .

 

[Adoniram]

I guess it would help in that it eliminates at least one cat (just one, right?). But I don't want to change the muffler. I like how quiet it is right now, and I'd rather keep it that way as this is a daily driver (in addition to weekend warrior stuff). So putting a Y-pipe in between stock headers and mufflers seems unproductive (other than the cat delete).

Is there any O2 simulator needed for the y-pipe? I'm not sure where all the O2 sensors are. Thanks!

 

[oljedi11950]

2 cats & I didn't need o2 sim ! And you don't think headers will make it louder ?

 

[wfo9]

This is very confusing information...

there are two sets of 02 sensors. One before the cats and one after the cats. the one before the cats are WB sensors and are what actually run the truck in closed loop operation. The ones after are strictly for emissions testing and verifying the cats are running efficiently.

There are also two sets of cats right next to each other. The primary cats are in font and are the real converter that are used once the motor is warmed up. The secondary cats are only efficient at startup when the primary cats are not warmed up enough.

What the simulators do is simply make the rear 02s act like they are oscillating between rich and lean on the 14.7 barrier. (because that is all a narrow band sensor really does anyway). They should only be needed when the primary cats are removed.

In 2013 Toyota added secondary air injection. the purpose of air injection is to light off cats faster by introducing fresh air on startup. So I guess it is possible they changed up the CEL trigger for the rear 02s to look for a lean spike on startup and basically detect a simulator.

That is the only thing I can think of, because normally air injection screws with 02 sensors and makes them useless during the air injection sequence.

 

[Adoniram]

That's very helpful information, and it also explains the additional port on the 13+ headers. From what you've described, that must be the air injection port.

For the sake of clearing things up for future readers (who may be as unfamiliar as I am with the stock exhaust), here's a diagram of the various components that the long tube headers would replace:

The image is lifted from the earlier version of the 4Runner, so you don't see the air port here, but the headers are definitely a different part number. For example, the right header,
2012: 1714031590
2017: 1714031610

Here's a real pic of the latter unit, with the air port visible:

The y-pipe would replace TWO cats as well (from what I can see). Basically, everything up to part # 12:

FWIW, I replaced the headers, up-pipe, downpipe and cats on my '05 Legacy GT (2.5 turbo) and it made zero difference to every day road noise. The stock mufflers do a great job. Yes, I left a lot of restriction in place, but I got a lot of power out of the parts I put on (plus a tune). More importantly, I was able to live happily with the build. No constant droning on the highway... I would expect the same from the 4Runner.

The real benefit to the headers (for me) is cat removal and mpg boost. I would do a high-flow cat y-pipe if it was available.

 

[Emery Smith]

Headers

Has anybody installed headers on a 2010? Been looking into it. The mods I have right now are the. S&b CAI and a Gibson Cat Back, and a Vrtune stage 1.5w pops and bangs because why not.