Question Maximum Air Flow Set up Help? LT Headers, Cat removal, exhaust? - Toyota Tundra Forums : Tundra Solutions Forum

samoan_souljah808 · #1 (**permalink**) 10-24-2008, 10:37 PM

So ok ive been researching for a bit now and this is what ive seemed to grasp. I want the DT long tubes, but my question is that there are 2 sets of cats after them right?

After the headers are the first set of cats then a little farther down are the 2nd pair followed by the muffler. So is the first set of cats removed when you install the DT LT's as well do you need to purchase o2 simulators...seperatley?

Ive read different things, that the second set of cats are useless and removing them will create more air flow and high flow cats provide no benefit seeing as new vehicles come with hig flow cats already. So if the DT LT's remove the first set of cats and I remove the second for maximum flow I now have zero cats (hypothetically).

I want the best set up for maximum air-flow, but want to be able to pass smog.

Opinions on the cat removal and high flow cats?

Also which is better in your opinion, the corsa sport single or banks monster. And for those that side with the banks which is better to you dual or single as far as looks, sound and performance?

Thank you for any help! I am fairly new to moding and have been trying to research as much as possible without posting something already discussed. Thanks a million!

samoan_souljah808 · #2 (**permalink**) 10-25-2008, 04:59 AM

any help from anyone? im looking to do these mods ASAP? Thanks Again!

v8hunter · #3 (**permalink**) 10-25-2008, 07:15 AM

See responses within message below

Quote:

Originally Posted by samoan_souljah808

So ok ive been researching for a bit now and this is what ive seemed to grasp. I want the DT long tubes, but my question is that there are 2 sets of cats after them right?

The car has 4 cats stock...2 for each side/bank.

After the headers are the first set of cats then a little farther down are the 2nd pair followed by the muffler. So is the first set of cats removed when you install the DT LT's as well do you need to purchase o2 simulators...seperatley?

The first set of cats are removed when you put the long tubes on. I'm not sure if this is true, but I heard here on the net that the front and rear cats are the same??? I ordered my long tubes from URD yesterday as well as ordered a pair of o2 sims. I am going to try welding some 02 bungs behind the remaining rear cats for the rear 02 sensors to see if I can run the stock rear O2s without a check engine light (and not actually need the sims).

Ive read different things, that the second set of cats are useless and removing them will create more air flow and high flow cats provide no benefit seeing as new vehicles come with hig flow cats already. So if the DT LT's remove the first set of cats and I remove the second for maximum flow I now have zero cats (hypothetically).

I don't think the 2nd set of cats are useless...they are probably there to clean up emissions even more than necessary (by law) to attempt to attain LEV or SLEV emissions certification. Theoretically you might be able to pass smog with just one set of cats, but without any cats you are very unlikely to pass...especially the visual. You would get the very best exhaust flow without any cats and a true dual exhaust straight off the long tubes, but I personally got tired of the stinky gas smelling exhaust on my 99 t/a and 03 cobra with catless systems so this time I'm going to leave one set on this go around.

It will be a week or two before I get my long tubes and put them on, but I will make sure to post my results.

I want the best set up for maximum air-flow, but want to be able to pass smog.

Opinions on the cat removal and high flow cats?

Also which is better in your opinion, the corsa sport single or banks monster. And for those that side with the banks which is better to you dual or single as far as looks, sound and performance?

Thank you for any help! I am fairly new to moding and have been trying to research as much as possible without posting something already discussed. Thanks a million!

07Sport · #4 (**permalink**) 10-25-2008, 04:46 PM

I wonder if theyd fail you w/ cutouts? I figure for pure flow, the LTs, and a cutout right after will by far give you the most flow.

samoan_souljah808 · #5 (**permalink**) 10-25-2008, 06:57 PM

Thanks for all the feedback. Cutouts are cool and a possibility for my friend and I. We've disscussed for his 300 srt-8 and mine cutouts, but thats probably not what im going to do, good set up though!

And ive heard mixed reviews from numerous people....will it pass smog since you can close it to a regular exhaust. also do you need to limit how much you drive with the cutouts open, some have said its bad for the engine?

Ok so if I get the long tube headers can you run a true dual exhaust with one set of cats and a muffler on each pipe and still pass smog, just one set up in mind?

But I'm leaning more toward putting th DT LT's and either trying the o2 sensor bung mod(depending on feedback) or putting the o2 simulators on and leaving the 2nd set of cats(possibly upgrading to magnaflow high-flow cats in the future)
followed by a Corsa performance sport single exit exhaust...any opinions on this set up?

would a dual in to a single muffler and dual out be better? (being that im not doing the true duals at this point)

thank you for all your help guys!