With downpipe, OP will be fully bolted. He's doing it pretty quickly, it seems, without time to evaluate the effect of each mod. I think that is a mistake. When too many mods are added in quick sequence or all at one time, and then a problem arises, it's damn difficult to figure out what is going on and to straighten things out. Getting in a hurry is a sure way to go zoom, zoom, boom.
I question the need for the CBE in OP's mods, unless it was just for sound effects, as the stock CBE flows so exceedingly well, even up to the maximum flow rate of the stock turbo.
He has a good intake and a reliable BPV running recirc as is needed (although stock BPV may actually work better, especially with his Hypertech flash). He's putting an FMIC on now. Not sure why he'd doing that before addressing the exhaust side a bit better, but I have no quarrel with that provided he knows that it does not make more power, merely allowing him to keep the power he builds before approaching heat soak, while giving up some spool up time and making some turbo lag due to the longer tubes.
Now as to the DP. The reason I held back and asked OP to read a bit (seems like he has not really read deeply into the threads) is that this is a very controversial subject with a lot of risks and benefits to weigh against each other. DP is not an easy install on this engine, even for those who are in the business of doing performance exhaust work. If he is concerned about CEL's he should probably stay away from catless, as they probably will come. If he is in a state that inspects, he clearly should stay away from the catless dp. The difference in pricing is largely, but not totally due to whether the dp has a cat. Those with cats cost more. Also some are one piece all the way to the CBE. They cost more. He already has a test/race pipe.
If he is in a state that does not test for emissions and he is prepared for the other side effects of running catless, then the catless dp will build more power and is a lot cheaper, even with the best construction. The TurboXS is a high quality piece. I got that just because both the dp and rp have good flex joints that make installation a bit easier and reduce the chances of vibration or mechanical noise from the dp bumping against anything under the car as the engine shifts on its mounts during WOT.
Installation is not for the meek and does require patience.
OP has a Hypertech flash. He can read and remove CEL's with its programmer, so I'm not sure what his worry is. The only CEL the catless dp should throw is from the rear O2 sensor trying to say "WTF happened to the primary cat?"
My concern for OP is that he will be fully bolted and I don't see that he has any type of engine monitoring equipment. He needs at a minimum a good manual vacuum/boost gauge that goes up to +25, and some way to check AFR's. Fully bolted, he should consider some type of data logging monitoring equipment such as Dash Hawk and take the time to learn how to set it up and read and understand the data.
The dp will raise boost about 2 psi. His Hypertech flash is going to let him see 18-19 psi, which is just a tad bit more than a catless dp/rp combo together would produce on the stock tune, but the flash will smooth out things and reduce the somewhat nasty quick spikes to 21-22 psi I was seeing running catless before the flash.
He's going too be dangerously close to increasing flow through of the engine from intake to exhaust in a way that maxes out the ability of his turob wastegate to bleed off excessive boost. He may encounter boost creep, a dangerous situaiton in which boost hits target fairly early in the power band and rather than holding, continues to climb above 18-19 psi as rpm increases. If that condition exists, he will have to find a way to either open up the wastegate (expensive removal of the turbo, opening up the wastegate port by enlarging the port and installing a bigger flapper), or he will have to reduce flow by adding restriction on the exhaust side, perhaps going to a high flow cat or even going back to his stock secondary cat in place of his test pipe. Otherwise I would not expect his engine to last long.
Also, some (a significant number) of owners here seem to run into fuel pressure problems when modding at the level OP seeks. He'd be wise to monitor that as well and might have a car that needs a fuel pump upgrade.
Also, running catless dp/rp will have some perhaps unexpected side effects. The exhaust will smell bad. Those of us who grew up in the era before catalytic converters and built and raced high performance cars know what raw, rich uncatted exhaust fumes smell like and we are used to it. If not, he will probably find that it is necessary to run his AC in "recirc" mode and not to spend too much time with the windows down at low speed. lol.
More importantly, however, runnign catless dp/rp will really make the exhaust quite loud and perhaps unpleasant, It may introduce headache producing drone at around 2,500 rpm. I had to actually add a 3 inch high flow straight through design reso (Vibrant UltraQuiet) welded into the middle of my race pipe to tone down the horrible drone.
I don't think there is any good evidence that adding a dp, either catted or not, will increase the risk of turbo smoking beyond the fact that without cats in the exhaust system, thingh that would have been vaporized by the heat of the cats, may end up coming downstream and out the tail pipe. That goes with the territory.
All in all, I find that running the TurboXS dp/rp combo with a good intake and the Hypertech flash is a very compatable and highly satisfactory way to build safe power. If I were to add an FMIC, I'm afraid that I would be pushed into boost creep.
But remember one thing. These cars (mostly due to the high pressure direct fuel injection) defy conventional thinking about mod compatability. Each car seems to have a mind of its own and identical cars with the same mods seem to frequently behave differently.
but i just got my turbo replaced and it wasnt because of the dp...at the time all i had was a test pipe and res. deletes and it was smoking...its the pcv valve thats at least what mazda told me...i have a ets tmic/cobb sri/stock bpv/corksport dp/cobb ap stage 2/ and denso 1 step colder plugs
