rnorthen

Have a 10 P30 with OE tune and would like a bit more sound and power, but concerned about passing inspection and don't want to install and then have to remove exhaust mods to pass.

Given that I believe that LTH are out, but removing the secondary cats and adding an x pipe would provide more power while allowing me to pass the emissions check.

Anyone in DFW who has any experience with exhaust mods? Would appreciate your take...

rentzington

texas doesnt do sniff test of visual inspection so you could do LTH and go catless and have a tune fake the o2's as being ready or you can do LTH and high flow cat's

you can certainly remove anything past the primary cats and still pass the test as long as your odbii says the monitors are on.

CarHopper

^ If you tune out the CEL the monitors wont set to ready.

o2 spacers (which will be finicky) would be the way to go and ensure the tune for headers doesn't prevent the CEL from popping up.

Secondary cat delete and res delete is the way to go for you.

rentzington

I was fairly sure tunes out there would show them as ready... Either way you can always use high flor cats with headers and keep the O2 monitors

Or just ditch the secondary and res

CarHopper

^ The tunes will allow the monitors to show ready as long as they are not programmed to erase the CEL you'd get for not having cats.

qjumpr

I ran full catless on my EVO, STi and WRX. Never had an issue. My WRX had the spacer for the O2 sensor, the others had tunes.

I have used the texaco on Frankfort and the tollroad, and also speed zone and some other small shop on McDermott and Alma in Allen. Never had problems with any. My C63 and CLK BS's have all had the second cat and res delete and they pass anywhere.

rnorthen

So it sounds like there are more options than I originally thought:

1. Cat back with secondary cat and resonator removal - with tune gain of what? 30hp? and a bit more noise when I get on it...

2. Full exhaust with LTH and no cats - with tune, gain of what? 70hp? and a significant increase in exhaust volume at all times...

Are those options about right?

roadtalontsi

legally you cant touch your cats... now to pass changing/removing secondary cats or catback wont matter at all. As far as running long tubes w/o cats or with hiflow cats it will all depend on your tune. I would definitely go with high flows - these cars burn a lot of gas and it'll smell. It also depends on where you get it done, in theory they could fail you based on a visual inspection. depending on the year of the car some allow 2 not readys and still pass. Just becareful with what you do, these cars get very very loud. You should probably hear someone elses before you do anything. Most of these owners have horribly loud exhausts that are raspy as hell. While my supra omega loud with a 4" straight through exhaust, i dont want that in my daily driven high dollar amg car.