[EdgyAsf27]

Is there any After market Downpipes that are high flow catted that are guarenteed no check engine light? Im from California and dont want to deal with smell of catless and check engine light. (Kinda torn between catless and high flow catted).

Also heard vrsf high flow catted dp are cel free but it doesnt say anything on their website about them and only heard this once lol.

Also wondering if MHD clears Check engine light since I dont want to use JB4 ever. Thanks in advance

[WoodE30]

I ran the VRSF catted Dps for about 500 miles w/o check engine light. IMO for the cost you're not going to find a better option than the VRSF catted dps.

[Smgs1992]

Mhd gets rid of CEL and as long as you have secondary cats still there is no smell. Catless wont pass visual inspection though

[EdgyAsf27]

Originally Posted by Smgs1992

Mhd gets rid of CEL and as long as you have secondary cats still there is no smell. Catless wont pass visual inspection though

Nicee, by the way for MHD, can I keep everything stock and fix the downpipe, or do I have to run a tune? Plus this is my first mod catless downpipes everything else is stock so Is it bad that I just install it without a tune or will it mess up my car. Thanks man

[EdgyAsf27]

Originally Posted by WoodE30

I ran the VRSF catted Dps for about 500 miles w/o check engine light. IMO for the cost you're not going to find a better option than the VRSF catted dps.

Nice, do the turbos spool loud? And did u have to run a tune for the cats or can you just leave them without a tune. Bc mines stock

[Smgs1992]

Youll run the tune for the DP fix. Not sure why you would get catless downpipes if you arent gonna tune it though. You can put it in stock mode however without a CEL. If you flash it back to stock tune though the CEL will appear.
Itll run fine with the stock tune i went a month or so like that before i tuned my car without any problem.
Definitely get a chargepipe before tuning though.
You do hear the turbos spool more. However i noticed the big change in sound after tuning surprisingly

[WoodE30]

Originally Posted by EdgyAsf27

Nice, do the turbos spool loud? And did u have to run a tune for the cats or can you just leave them without a tune. Bc mines stock

It sounded a little better, but I had FBO, including inlets, outlet and at one point had the VRSF street exhaust. If you're stock id recommend at least running JB4 or MHD. I wouldn't do the VRSF catted DPs for your first mod.

[mweisdorfer]

Originally Posted by EdgyAsf27

Is there any After market Downpipes that are high flow catted that are guarenteed no check engine light? Im from California and dont want to deal with smell of catless and check engine light. (Kinda torn between catless and high flow catted).

Also heard vrsf high flow catted dp are cel free but it doesnt say anything on their website about them and only heard this once lol.

Also wondering if MHD clears Check engine light since I dont want to use JB4 ever. Thanks in advance

I think what a lot of guys do in California is change out their Catless downpipes to the OEM cats on the day they are to get tested and then change back once they get home.

It's not a very involved process. It can be done in an hour and some change to be honest

[Bimmer_Engineer]

I must really not understand whats involved in swapping down pipes if this can be done in an hour and change...

It takes me 10 minutes on each end to get the car on jack stands...

[roadkillrob]

I have the ARDesign catted dp's which are supposed to be pretty good cat's, they went about a year or 2 and maybe 4k miles without an issue and then started to throw some efficiency codes when you got on it a bit. I suspect there isn't much that won't eventually start throwing codes and I use a DPFix now, but you will pass a visual I guess even if they eventually throw codes.

[mweisdorfer]

Originally Posted by Bimmer_Engineer

I must really not understand whats involved in swapping down pipes if this can be done in an hour and change...

It takes me 10 minutes on each end to get the car on jack stands...

You just:

1) put the car up on 3 jack stands (10 min)

2) Remove the under tray - (2 min)

3) undo the 2 bolts on the power steering rack & move out it out of the way (7 min)

4) undo the 2 pre cat O2 sensors (10 min)

5) undo 2 post cat O2 sensors (7 min)

6) undo the 4 bolts at the mid-pipe

7) undo the 2 v-clamps at the turbos & remove the down pipes (7-10min)

Install cats in reverse order

As long as your bolts are greased with cooper or nickel based anti-seize, they should come out & reinstall no problem (1x) a year; especially in California where they don't use salt on the roads in the winter & do not have 4 seasons. It also helps to have grade 8 bolts & nuts at the mid-pipes too. The only thing you might have to replace is the mid-pipe gaskets.

So, maybe 2 hours tops......

Putting the v-clamps on loosely & clocking pipes correctly so the mid-pipe connection will happen w/out too much stress can be a little tricky.

[mweisdorfer]

Originally Posted by roadkillrob

I have the ARDesign catted dp's which are supposed to be pretty good cat's, they went about a year or 2 and maybe 4k miles without an issue and then started to throw some efficiency codes when you got on it a bit. I suspect there isn't much that won't eventually start throwing codes and I use a DPFix now, but you will pass a visual I guess even if they eventually throw codes.

Cobb makes a nice set of HF catted down pipes for around $850. In fact, their exhaust set up (which isn't cheap) that has HF catted downpipes sounds pretty good.


https://www.cobbtuning.com/products/exhaust

[Bimmer_Engineer]

Originally Posted by mweisdorfer

You just:

1) put the car up on 3 jack stands (10 min)

2) Remove the under tray - (2 min)

3) undo the 2 bolts on the power steering rack & move out it out of the way (7 min)

4) undo the 2 pre cat O2 sensors (10 min)

5) undo 2 post cat O2 sensors (7 min)

6) undo the 4 bolts at the mid-pipe

7) undo the 2 v-clamps at the turbos & remove the down pipes (7-10min)

Install cats in reverse order

As long as your bolts are greased with cooper or nickel based anti-seize, they should come out & reinstall no problem (1x) a year; especially in California where they don't use salt on the roads in the winter & do not have 4 seasons. It also helps to have grade 8 bolts & nuts at the mid-pipes too. The only thing you might have to replace is the mid-pipe gaskets.

So, maybe 2 hours tops......

Putting the v-clamps on loosely & clocking pipes correctly so the mid-pipe connection will happen w/out too much stress can be a little tricky.

It sounds so easy...unfortunately my experience with this car tells me it's rarely as easy as it sounds...

[mweisdorfer]

Originally Posted by Bimmer_Engineer

It sounds so easy...unfortunately my experience with this car tells me it's rarely as easy as it sounds...

If you live in the rust belt or a state that uses salt on the roads in the winter, the first time you take the cats off, it can be a B@tch, at the mid-pipe connection.

Don't panic. Just use a small sawzall with a Diablo Carbon Tipped blade & have a dremmel with a HD blade handy. DeWalt makes a nice, small Sawzall.

If you can't get the bolt out of the hole of the cat, use a torch w/ yellow gas and heat it up to red/ white hot. Then use a punch with an 8# mini sledge. It will come out.

Use Grade 8 bolts & nuts when you replace them. At the mid-pipe connection. Make d@mn sure you slather them up with copper or Nickel based anti-seize. I'd also put a little of the same anti-seize on the v-clamp bolts. It never hurts to replace the v-clamps, especially if you are over 100k in them.

Personally, I like the mid-pipe gaskets at BMS. I think they provide a better seal. Yes, you can get a code if you don't seal that connection up air tight.

The best deal running for Catless downpipes are MMP for $199.00. They fit. I have them.