LDai1219

I was just wondering, how many people tried taking off our 3 cats and added ONE aftermarket cat converter on the 3G TL? And if we did that, would the TL be able to pass smog test? Also, would ONE aftermarket cat have any advantage/disadvantage over 3 cats?(Performance wise).
Thanks in advance.

stillhere153

iTrader: (1)

The only emissions approved cats for the 3g are the procats... Swapping or gutting the 3rd cat may or may not pass emissions inspection

Royce Han

umm, i think its safe to say that i dont think anyone has ever done what you just described. doing that to your still- oem ecu'd TL would cause the check engine to Never go away. theres 2- o2 sensors per cat. of bank 1 and 2- both up front cats. passing a smog test? -you automatically failed if your check engine light is on when testing. as far as performance? the only time ive heard of or seen anyone fiddle w/ the 3G TL cats is for when changing to the Pro-Cats.

maybe just one exception-well kinda sorta -where i can say that i know of one guy who used to have a 3G TL motor-technically, where he fiddled with his three cats just like how you said. he took them off and let that check engine light shine on. his J32A3 motor was really the 3G TL -bare cyl. block , stroked to a 3.5L using 05 MDX internals ; crankshaft, c.rods, etc.. except for the pistons which he chose the 02 CL type -s ones for their lower comp. ratio than our stock J32A3 pistons so he could efficiently run his huge custom GT35R turbo - thats what i meant by "fiddling with his cats" since he obviously had to have had a custom turbo mani fabricated in place of where the ol cats used to be. his greddy e-manage ecu was a true complete standalone setup so his check engine light was merely an annoying yellow light rather than the usual performanvce killer that it is. the car was an 03-05 AV6 6MT Coupe .made 350 at the wheels- sounds kinda wuss for an Extrudehoned 3.5 turbo setup but that was only at 8.5 lbs. boost on a GT35R turbine- with max HP rated at 550+ HP.

so unless you just bought a set of pro-cats or you like to do big thing$$$ like the AV6 guy, you really dont want to be messing with yer 3way cats like that.

MrHeeltoe

iTrader: (1)

PS, NO aftermarket cats are legal in California for this car (I'd venture to say in NY and MA as well, but don't quote me).

Bearcat94

Not an expert here, but pretty sure there are NO sensors in the 3rd cat. So, no CEL if you gut, remove and/or replace the 3rd Cat.

I am sure I've read of others putting a test pipe in place if the third cat with no CEL problems.

stillhere153

iTrader: (1)

I think NY is illegal to modify one, but if it becomes damaged you can in fact get a replacement for one, but yea many states have strict guidelines

as for passing inspection in nyc, it cant pass since I don't believe there is a visual inspection... only a nox level requirement

I hate cars

For what it's worth, I had a friend run my car on the rollers after I gutted the 3rd cat and it still passed easily. No 02s on that one either so no light.

I'm pretty sure the law says the aftermarket cat(s) can't be farther downstream in the exhaust than the factory cats. Besides, two cats (one per bank) will flow better than one with the full exhaust flow.

dmb4325

But by putting one cat in place of the back one will it sound and better? are there cats besides the procats that would work, like i have been reading something about Random Technology, just cant find very much about them

ib18c1

iTrader: (6)

possible to run o2 simulators on our car to get rid of the CEL?

stillhere153

iTrader: (1)

yah the defouler method works always

I hate cars

Random Technology makes good high flow cats. I ran one on my turbo car in the old days but eventually it was too much of a restriction. Unfortunately I doubt they make anything for the TL. I'm sure you could order something with the appropriate body dimensions and have them welded in the factory cats' place.

I hate cars

Defouler method doesn't always work. I can name two friends' cars where it prolongs the time it takes for the light to come on but it always comes back on. Anyone know if they still make simulators?

stillhere153

iTrader: (1)

I dunno, I mean one of my friends did the defouler method on his volvo.. light never came back

pretty sure they still make simulators

dmb4325

Well then does anyone know what the inlet and outlet are on the third cat so I could order like a magnaflow universal or something along those lines?

dmb4325

When you gutted the third cat, did you get a louder sound out of it?

Kennedy

iTrader: (2)

Search Megan racing... There's a test pipe that fits, but why? It's been proven that it provides no gains.

Have fun polluting for no reason other than to pollute.

JCL622

your best bet for gains would be ATLP j-pipe, or excelerate's J-pipe when it's out

and then a ATLP or excelerate exhaust setup -> both indicate good gains.

if it's the sound you're going for

just do aznbo's Stage 1-4 exhaust mod, if you get to stage 2-4, the straight pipe is probably gonna be a 2.5"

so if you wanted to go further, it'd be a 2.5"/2.25" Magnaflow Y-pipe, and then 1/4inch Offset/Center, 20inch Overall Length, 14inch Body Length mufflers, after which you just take your pick of exhaust tips or be like me and weld the stock ones onto these.