Im looking to get a Downpipe (catless) for my R56. Its a 2007, which I got when they first came out and I have heard that on some 2007 models that dont have issues with the CEL when installing a catless DP. Can anyone confirm this? I REALLY want the Riss Raccing DP and I dont care very much for the ED Downpipe with its $600 price tag.

 

I've never heard of any catless downpipe that didn't throw CEL's, except maybe if you get Riss Racing's O2 sim, which doesn't even work yet.

Maybe just me though, other people can chime in on this.

 

I think you are referring to CELs on a catted dp. The 2007 seemed to be OK with catted DP until they get a reflash of their ECU. Some manufacturers seem to do better than others. MY 2008 and beyond seem to have more problems.

Catless dp seem to all get CELs.

 

I dont really mind the CEL. But if the driveability of the car is effected, then that kind of defeats the purpose of a performance upgrade. Who is running a catless DP here? Are you having any drivability problems?

 

Yes a CEL will affect your car. In some cases it will throw the car into limp mode. But it will definetly effect your gas mileage and it will rob a lil bit of power but not anymore then what you would gain.

 

The blurb you heard about no CELs on downpipes would apply to catted downpipes, especially those made by Exhaust Depot. There is no question you'll get a CEL with no cat. Trust me, it will show itself!

I have a catless '09 and use an O2 sensor extender to slow down the rate at which the CELs will occur. I have a P0240 and P0136 code brewing all the time. I've went into limp mode ONE time in 25,000 miles but then I just clear the CEL and I'm back to normal. The car runs great and the torque gain from my exhaust is really entertaining.

I've driven almost half an hour on the freeway without a CEL showing itself. When you look at the catted downpipes out there, the cats are still pretty huge, but at the same time claim to be high flow. No one has showed any respectable dyno results with before/after comparisons with any type of downpipe. We can just hope that they flow better. But hell if there is less restriction you're going to have higher exhaust gas velocities in the downpipe!

 

^^^^ Good point it is one that I would wait on until someone comes out with a definitive 02 simulator that works 90% to 100% of the time. The reason I give those numbers is because I had a sim on my Spec V and it work about that regularly and if you get a catless Dp get an OBDII reader with the capability to clear codes becuase you are going to be doing it a lot.