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Preface:
I see this mod come into question pretty often so I figured I'd just compile something quick for the members new to 3G TL's or new to car modding in general.
Some quick background information:
The stock 3rd catalytic converter (commonly referred to as "3rd cat") is located between the J pipe and the catback exhaust. It has the following features -- 600 cells (Type-S) 900 cells (base), 2.25" diameter.
Definitions:
Race pipe - generally referring to a non-resonated pipe with flanged ends that will mate up to the J pipe flange and the catback exhaust flange.
Test pipe - same as above except it is resonated.
High flow cat - essentially the same as the stock 3rd cat but with less restriction (less cells).
The MOD:
This mod removes the stock 3rd cat and replaces it with ONE of the above options.... ONLY ONE CAN BE USED. This decreases the exhaust flow restriction resulting in better performance and a slightly different exhaust tone.
Available products for this mod:
1. ATLP race pipe - $125 http://www.acuratlparts.com/products/4/
- T439 stainless steel construction
- uses thick, SOLID mild steel flanges
- 2.5" Diameter throughout
- allows stock heatshield to be attached for added protection and for the stock appearance (might help with visual emission inspections)
3. R-V6 test pipe - $74.99 http://r-.ecrater.com/product.php?pid=2481591
- T304 stainless steel construction
- TIG welded T304 flanges
- 2.5" Diameter throughout
- resonated
- since it bulbs out, it looks similar to the stock 3rd cat
4. ATLP high flow cat - $325 http://www.acuratlparts.com/products/14/
- stainless steel construction (grade is unknown)
- 200 cell
- cross sectional area increased by 12% over OE
- allows stock heatshield to be attached for added protection and for the stock appearance (might help with visual emission inspections)
5. R-V6 high flow cat - $249.99 http://r-.ecrater.com/product.php?pid=2527900
- stainless steel construction (grade is unknown)
- 300 cell
- cross sectional area increased by 12% over OE
- this is a pre-order item. Not readily available.
I hope this helps!
Feel free to add something I missed or fix something I got wrong.
Nice job jmkiang. Looks like everything is ok, but then again I'm kinda sleepy heh heh. I'm sure this will help out new-comers very much with your informative thread
What a big coincidence... I was telling my buddy [who owns a 6G Celica] the differences between race pipe and the test pipe... and I stumbled across this. I ended up copy-pasting it to him hahah.
could you somehow add to your post which ones are loudest? seems like that is an issue alot of people post about also..
good thread!!
Well, this mod doesn't really make your exhaust any louder... maybe a TINY bit.
Race pipe would be the "loudest", then the test pipe, then the high flow cat.
Originally Posted by o4Komodo
What a big coincidence... I was telling my buddy [who owns a 6G Celica] the differences between race pipe and the test pipe... and I stumbled across this. I ended up copy-pasting it to him hahah.
^ I would guesstimate a couple whp (1-3) with STOCK everything else.
The thing with exhaust mods is that they "build off" each other. The more aftermarket exhaust mods you have (meaning the less restriction you have), the more you'll benefit.
In the rest of the automotive world, "test pipe" refers to an unresonated straight pipe in place of the cat.
Not to start an argument but again, due to the minimal gains of this mod, I would not do it unless it's free which in my case it was. If you're running a supercharger and flowing a lot more exhaust, it may be worth the money for a test/race pipe.
Resonated and non-resonated should flow the same for all intents and purposes. With the stock exhaust there's no reason to get the resonated unit.
A high flow cat on a non supercharged TL will probably make just as much power as a test/race pipe. Once the TLs get into the 450rwhp range, no single highflow cat is going to flow enough and the test pipe will be mandatory.
Has anyone done a test pipe and muffler delete? I want just a little noise, and a little better flow but would still like for the car to still be on the quiet side.
In the rest of the automotive world, "test pipe" refers to an unresonated straight pipe in place of the cat.
Not to start an argument but again, due to the minimal gains of this mod, I would not do it unless it's free which in my case it was. If you're running a supercharger and flowing a lot more exhaust, it may be worth the money for a test/race pipe.
Resonated and non-resonated should flow the same for all intents and purposes. With the stock exhaust there's no reason to get the resonated unit.
A high flow cat on a non supercharged TL will probably make just as much power as a test/race pipe. Once the TLs get into the 450rwhp range, no single highflow cat is going to flow enough and the test pipe will be mandatory.
All input is good, for or against. Thats really what this thread is for.
However, you seem to be against modding the TL (performance-wise) so I'm not surprised at your statement.
Its a relatively inexpensive mod (especially with GBs) so people like it.
I'm not sure how you did yours for free but most people don't have access to TIG welders and SS pipe... or flanges for that matter.
These options are nice because it allows you to swap your 3rd cat back in if/when selling the car.
All input is good, for or against. Thats really what this thread is for.
However, you seem to be against modding the TL (performance-wise) so I'm not surprised at your statement.
Its a relatively inexpensive mod (especially with GBs) so people like it.
I'm not sure how you did yours for free but most people don't have access to TIG welders and SS pipe... or flanges for that matter.
These options are nice because it allows you to swap your 3rd cat back in if/when selling the car.
Don't take anything is say serious or personal, it's all in fun and for discussion. I'm against modding a TL because even after thousands of dollars you will have a 13 second car at best. It's just not a good platform to start with. I really like my TL and 68,000 trouble free miles is awesome.
The reason I don't suggest this mod on a stock car is it's not much of a restriction in stock form. You're talking 1-2hp for $65.
Now after you install a blower or nitrous, you may get 15hp from removing the cat, making it worth it.
You are right, one of the advantages is you can put it back to stock. I have a friend that does smog so I took mine in, removed the thrid cat and tested the car. It passed without the third cat so I hollowed my stock one out and put it back on the car. That's how I did it for free. This was also before the test pipes were offered. I don't have a before dyno but mine made 209.7hp after gutting the cat which is about right for a stock auto.
^ I agree. It isn't a great car to mod (performance wise) but its still fun. LET US HAVE OUR FUN DAMMIT!
A good reason to do this mod would be to "prepare" the TL for a blower. Thats what I keep telling myself.... one of these days
Anyway, go away! This is information for the newbs so they can make their own informed decision. Haha
To tell you the truth I thought this thing was $200 when I first started looking at it. $65 isn't that bad.
I wish you lots of fun in modding the TL. Sometimes I get too caught up in the bang for the buck and competitive racing. As long as you have fun modding, that's all that matters.
So is there a consensus for the most flow and still pass emissions testing?
ie: remove both primaries and keep the 3rd , or remove the 3rd and install 2 new high flow primaries?
I'm asking because one or more of my cats are bad because I can smell it at heavy throttle so if I replace 1 I'm just going to do the whole thing. And get a j-pipe of some kind. I saw a pipe for $150 https://mufflerexpress.com/products/...waArvCEALw_wcB
Intake, stock primary cats (manifold cats), rv6 v3 y pipe w/ 3rd cat delete, secondary muffler, resonator delete, and stock tailpipes. It has a rasp at about 3,500-4,300. Im satisfied with the sound for now.
Good thread here from the past. My 3rd cat rattles and I can hear it “muffle” the sound. Can hear some sponge material shaking about as well as the metal on metal rattle that’s annoying.
The flanges on the cat are all rusted together so I won’t be able to unscrew and remove it as it was meant. can I just have my shop cut off the cat and flanges and straight pipe it Like below?
Cut in the yellow, straight pipe the middle.
just did a stage 3 (mid-muff delete + Dynomax 23215 resonator swap), so that’s what’s been done to the car so far. Looks like a race pipe (basically what I’m doing since it’s a straight pipe) seems not to increase volume, but just make it more clear-exactly what I want. don’t want rasp or drone though.
Ontario, Canada so not really concerned about legality or inspections.
Hey all....I hope this question is adequately "on topic" for this thread...I have a 2007 TL-S, and one of my exhaust manifolds is cracked. I also need to replace my RV6 jpipe asa the flex sections are loose, and noisy. My question is: If I replace both stock exhaust manifolds with the RV6 package ($1229 on their website, includes 3rd gen J pipe, and 2 HFPCs + assorted hardware)-is there an ADDITIONAL mod to get the car to pass smog inspection here in NH?
Thanks in advance for the WEALTH of knowledge here!!!
THE *unofficial* 3rd cat delete mod thread
Thats what I keep telling myself.... one of these days 
