My next mod is a dp but im still debating if to go with catless dp or high flow cat dp. My two concerns are if one will provide more power than the other or it does not matter? my second concern is will i pass smog emmisions with either catted or catless dp? or just keep my stock down pipe? Thanks

 

No chance in hell you will pass any inspection.

 

how about with a high flow. will i even pass.

 

Catless will not pass. High flow cats typically pass, thats your best bet if your worried about emissions.
Going cat less with an lsj doesnt warrant the minimal results (maybe +3-5hp), if it were the LNF different story, turbo cars + cat less = nice results.

 

i always pass inspection without a cat

 

I don't know about other companies but Hahn states only a 5% difference in power between a catted dp and catless dp

 

i have basically the same mods as you. i did have a catless, but it was very raspy and actually i lost power, i had less boost and that lovely sc whine was gone. went highflow and got back the power, boost, and whine. plus without cat you will throw a CEL unless u get tuned and shut down rear o2 sensor. as if it will pass inspection or not, yes it will pass emissions, but if they look to see if you have a cat or not they will fail you.

 

I gained quite a bit of power when I went catless. No dyno proof :/

 

it was seat of the pants dyno for me. i can say for sure i did lose boost and whine without cat.

pre dp-16psi
3" catless, header-14.5
3" catted, header- 15.5-16

 

i never lost any power

 

how do you do that?

 

Got no check engine lights and i just put the stock muffler on.

 

when you get rid of a restristion you will loose boost but that is not a bad thing

 

^^ Winner.

You just have to know which inspection stations don't check that kind of stuff

 

You didn't lose power unless something was wrong. If you lost boost is was because your airflow went up. Which is a good thing. Unless you tested it, I doubt you lost any and in fact the gains were so unnoticable that you chalked it up as a loss in power.

 

Only fun thing with catless is the flame....
other than that its a pain if u cant find someone for inspection or hptuners
I replaced mine with Vibrants highflow cat but still throw 1 code

 

Very misinformed statement.

The boost increase your seeing is called RESTRICTION. Which is NOT GOOD.

You did not lose any power unless something else changed.. like the size of your exhaust.

 

Look at it this way and engine is a air compressor the more air you can pump in and out the more power you will make

John