Catless DP coming from the US

[MZSPD6]

About 2 weeks ago I bought a Catless DP from the states, it will arrive Wednesday next week and I'm starting to get a bit nervous lol

I did my research on 247mazda.com and the DP got a really good review from the local US guys. I'm starting to think my MPS will be extremely loud and angry.....

I have already installed a custom cat-back and CPe CAI. About a month ago I had the EcuTek tune done at S&J Automotive and came up with an impressive 173kw's.
S&J will be installing the DP and retuning it on the dyno in the next few weeks.

I am most worried about turbo smoking issues, is there something I should do to stop this from happening?

What gain in kWh's/torque would you expect from the DP being installed?

Is my MPS going to be that loud that it will drone like hell and also get the attention of the police? (Cat-back now has no drone and sounds sweet!)

Any info would be much appreciated and I will also keep everybody updated on progress!

Thanks, Mark

[AD07]

Probably will be illegal, for both emmisions & noise. Catless = track use only.

[Yeldarb]

You can always add a 200 cell cat to aid in emissions issues like I'm doing in a couple of weeks. Won't affect performance. I'm doing it to stop the CEL coming on which it's been doing since installing the BM DP.



As for noise, it shouldn't cause too much of a change. It made my car sound better in fact. Now I have a 3" Open custom system I think it sounds awesome with the DP.

You should be fine in my opinion.

[Nuliaj]

Unless you're pushing for absolutely maximum hp (in which case you'd want a screamer pipe) there's little gains between a catless and a catted dp. There's really no good reason to run catless for a street car. US forums will say otherwise but depending on the state, they don't have as stringent emission laws as us, and they're incosiderate SOBs. Smoking will be more obvious without a cat, not to mention the smell. That's the next worst thing, driving behind people running catless.

Yeldarb I don't think that is going to fix your CEL issue. If you look at the picture below you can see there are two O2 sensors. In the stock system the two O2 sensors will give differnt readings due to cat number 1. What triggers the CEL in a catless DP is that the ECU compares the readings from the first and second O2 sensors and if they're too similar (which they will be now there isn't a cat to initiate the chemical changes) it will throw an CEL to do with CAT efficiency IIRC. From what I can see of your picture, you're adding a cat at the second cat position which has no sensor after it. You'll need to move the O2 sensor back after the cat in order to get rid of the CEL, but that will mean you'll need to to make further modifications.

[KRNAGE]

i found adding my DP made my MPS quieter or maybe a different tone so I guess it depends, thats with adding a manifold. but i guess it all depends

you may want to get a re-tune after installing the DP

[MZSPD6]

i found adding my DP made my MPS quieter or maybe a different tone so I guess it depends, thats with adding a manifold. but i guess it all depends

you may want to get a re-tune after installing the DP

Yeah I will be getting it retuned at the same time the DP goes in, I am going to buy a hiflow cat and cut/weld it in to the DP.
Sould be good, really looking forward to it

So no info regarding stopping turbo smoking before I innstall the DP, I have read an oil reducer will do the trick???

[KRNAGE]

i haven't had to use anything, its the luck of the draw weather you smoke or not, but i haven't had an issue

[luke 3mps]

what boost are you running? if its standard or lower u may be ok..

[MZSPD6]

Before the tune I was 14psi and after sat at 16psi, I don't want to push the car to the edge as it is my daily.

[Yeldarb]

Unless you're pushing for absolutely maximum hp (in which case you'd want a screamer pipe) there's little gains between a catless and a catted dp. There's really no good reason to run catless for a street car. US forums will say otherwise but depending on the state, they don't have as stringent emission laws as us, and they're incosiderate SOBs. Smoking will be more obvious without a cat, not to mention the smell. That's the next worst thing, driving behind people running catless.

Yeldarb I don't think that is going to fix your CEL issue. If you look at the picture below you can see there are two O2 sensors. In the stock system the two O2 sensors will give differnt readings due to cat number 1. What triggers the CEL in a catless DP is that the ECU compares the readings from the first and second O2 sensors and if they're too similar (which they will be now there isn't a cat to initiate the chemical changes) it will throw an CEL to do with CAT efficiency IIRC. From what I can see of your picture, you're adding a cat at the second cat position which has no sensor after it. You'll need to move the O2 sensor back after the cat in order to get rid of the CEL, but that will mean you'll need to to make further modifications.

Good advice, Troy is experimenting with moving the second O2 sensor after the CAT. It has helped with less CEL's, but I think I just need a better performing CAT. Another Brisbane member with a Gen II installed a 200 cell Cat with good results. I.e. No CEL's.