High Flow Catted Downpipe by RRM / Hi-flow Cat DP

Best/last mod of the year! woot woot!! (for real, this time)

My new sink trap!

RRM High Flow Catted Downpipe Review:

I got a good deal on the DP on Cyber Monday, and it went under the tree “from my wife” for Christmas. The recording studio is pretty slow at the end of the year after Christmas, so I had some time to borrow some jack stands & jack and installed the Catted Downpipe. The part is stainless steel, so it looks amazing, the welds were solid, and it fit perfectly. At first, I loosely bolted it to the exhaust and tried to put the clamp back on to the turbo, but it was too difficult to get a tight seal. I recommend loosely bolting the top clamp first, and then tighten up the bottom bolts to the exhaust and mounting plate. I was not able to re-use the factory heat shield, as there were no mounting tabs on the new downpipe. It could still be bolted at the top, but my guess is that you may hear the heat shield flapping around in the engine bay. It looks pretty sweet without the cover, but I may get some (orange) heat wrap for it, instead of the cover. I’m not sure if that would accomplish the same thing, but they are only $23 on ebay.

First thing I did was start it up, and damn, does it sound nice! It’s very similar to the straight piped exhaust, but has a deeper tone, but gets more aggressive as the RPM goes up. At idle, it’s only a few decibels louder, but when you step on the throttle, it opens up and sounds MEAN!! I took my foster daughter to the suburbs on the highway, and she noticed it right away – she told me the car sounds “sexy as Hell.” When it starts, especially in the brick garage, it sounds BIG! Everyone is usually surprised when I tell them it’s only a 1.4L.

I did three engine cycles right away, and no CEL. Checked the pending codes as well, and the car was happy. I simply used the factory O2 sensor, which attached perfectly to a connection on the new dp.

As far as local, city driving, the turbo now spools earlier, under 2000 RPM, instead of 22-2300 RPM. The turbo used to hit like a brick wall at that rate, but now it comes on much smoother. I wasn’t digging in, at first, and I was monitoring levels and listening to the change in exhaust sound. It got much raspier as the RPM went up a bit, and turned a few heads, as well. My turbo used to hit hard, but then seemed to die down a bit over 3500 rpm, and the most turbo boost felt (butt dyno) was at 2200-2400 RPM. Now, however, it comes on smooth at 2000 RPM and feels strong all the way up to redline! I did a few 0-60 runs getting on the highway, but I have some practicing to do. I thought the traction control should be off, but I was spinning all over the place, and couldn’t get a decent time.

A few weeks after the installation, I do get a pending P0420 alert, and doesn’t go full CEL until 20+ miles highway driving, quicker if driving aggressively. I did buy an O2 spacer, but haven’t put it on, yet. I will report back, once I do that.

*update 01/19/2016

Little update, this morning the CEL went away on its own. Ironic, as I was on my way to the muffler shop to add the spacer. I deleted the factory 18″ resonator, as it wasn’t really doing much anyway, and I had a larger diameter (2.5″) resonator installed. It’s still 18″ but a bit more efficient, and sounds more growly, instead of raspy and harsh. In addition, I’m a music producer/engineer, so my listening is also critical in my ride – this was a great mod, IMO.

Anyway, the CEL for P0420 went away, but then I had a pending P0139 code – no CEL. As Jimmy was putting on the resonator, i asked if he would pop the O2 spacer on for me, which he did. I was feeling far too lazy to jack up the car, lose the belly pan and fight with it on the cold garage floor in -10º F weather. It was well worth the $10.00 to me.

So far, I have no CEL – I will update later, after 100 miles, or so.

Here are some pics of the RRM High Flow Catted DP – I forgot to add them with the review:
50 miles or so – the cheap $15 O2 spacer worked fine – no CEL, no pending codes.

O2 Spacer: (from BigDaddiesGarage.com)