[Steakpizza]

Hey guys,

I want to go Catless Stage 2 with my 320i but emissions means I would have to replace the cat yearly while I get inspected. Has anyone had any luck with high flow cats? Also, could I run the Stage 2 BM3 tune fine with a high flow?


Thanks

[BrysonDM]

Originally Posted by Steakpizza

Hey guys,

I want to go Catless Stage 2 with my 320i but emissions means I would have to replace the cat yearly while I get inspected. Has anyone had any luck with high flow cats? Also, could I run the Stage 2 BM3 tune fine with a high flow?


Thanks

You can run it fine with a high flow, just don't expect full power gains, and don't have any gnarly burble settings, or you'll forsure be needing a new car every year! Best of luck!

[Steakpizza]

Originally Posted by BrysonDM

You can run it fine with a high flow, just don't expect full power gains, and don't have any gnarly burble settings, or you'll forsure be needing a new car every year! Best of luck!

Awesome. I'm willing to give a few HP to save changing the cat every year lol.

[sqwinny]

Once you learn how to do it and have access to a lift, installing and swapping down pipes is easy under and hour for sure.

[BrysonDM]

Originally Posted by sqwinny

Once you learn how to do it and have access to a lift, installing and swapping down pipes is easy under and hour for sure.

Having free access to a hoist/lift is pretty tough to come by if you don't work at a dealership or shop. For his application I think a 200cel high flow would by far be the better option. Especially given the fact that he has to get it tested every year for emissions. Because even if he had to pay someone to do it, prodemand time states it takes 3 hours to change, so paying that twice a year, would easily be just under a $1000.

[sqwinny]

Other idea. Install catless downpipe and install universal cat further downstream. You can add and remove it with exhaust clamps on jack stands whenever you choose to pass the smog test. Worth a shot. Otherwise catless downpipe it is.

[Steakpizza]

Originally Posted by BrysonDM

Having free access to a hoist/lift is pretty tough to come by if you don't work at a dealership or shop. For his application I think a 200cel high flow would by far be the better option. Especially given the fact that he has to get it tested every year for emissions. Because even if he had to pay someone to do it, prodemand time states it takes 3 hours to change, so paying that twice a year, would easily be just under a $1000.

Yeah I have tried doing it myself. Issue is that I barely have room under the car, and I could not for the life of my undo the bolts holding the DP in place. I didn't want to fuck it up either lol. I have a buddy who's working in a shop that can do it, so I'm gonna see what his quote is. Worst case is that I'll go catless now, then have him replace with a high flow when inspection comes around.

[Steakpizza]

Originally Posted by sqwinny

Other idea. Install catless downpipe and install universal cat further downstream. You can add and remove it with exhaust clamps on jack stands whenever you choose to pass the smog test. Worth a shot. Otherwise catless downpipe it is.

The N26 has two cats, N20 only has the one by the front of the car. You're saying I could have a shop install a faux cat? Never heard of anything like that lol, I have an AWE exhaust and definitely don't want to mess with it.

[sqwinny]

I was referring to a real cat, you just relocate it off the downpipe. Not "faking emissions." As you state you have a full awe exhaust system, I'd hate to cut it up to essentially make it so you could swap a test pipe and a cat converter within that.

If you still have your stock exhaust, it's possible. Just swap the mid pipe with an additional cat, extend the o2 sensor to behind the 1st cat(relocated cat) and you should be golden. The issue is having your stock ecu stating the o2 sensor "warms up fast enough." Not sure how far PA goes in that regard, but on a warm car it would pass the actual sniff test.