I have an opportunity to change out my down pipe while having other work done (turbo rebuild by G-Pop Shop and likely a manifold upgrade to WMW) and I have the itch to do the DP upgrade.

Question is, which do I go for. I currently have an 09 MCS that has many mods. My questions are as follows.

1) Is the stock JCW DP that I can buy from RealOEM any different from the stock MCS DP?

2) I am guessing that the JCW DP will not lead to any CEL's but I am not 100% about that. Can anyone confirm that? Specifically, putting a JCW DP on a regular MCS.

3) If you didn't care about CEL's but did care about passing emissions, which catted DP would you recommend and why?

 

How often do you have to pass emissions?

I have the Evolve catless DP and it makes a big difference in power and sound. Even if it fails it did not take long to install, I didn't put the nose in service mode, I was just real tenacious with the small shield bolts.

So its just a couple of hours from catless back then then swap to catless. I have to pass Maryland emissions every 2 years. SO if the tune doesn't remove the CEL in a way that it passes its still not that big of a deal to swap.

The gain is worth it compared to a catted pipe in my opinion.
2010 MCS Alta, Evolve Tune catless DP, Big FMIC

 

JCW cat is the same as the MCS cat.

I don't think that there is a HP downpipe that consistently does not create a CEL. Here in NY, my dealer says that if the car has a catted DP, and no CEL, it will pass emissions. There is no sniffer test. Since the JCW has only one cat (in the DP), the dealer says that I'm legal with that.

I don't know if your state is different with regards to the testing or the cat spec.

I hope that I didn't confuse things more....

Have fun,
Mike

 

I believe that all high flow DP will cause a CEL. There is a rumor out there that NM is going to be releasing a high full DP that does not.

 

Most places will just plug into the OBD port on the car and scan for codes. If your tune disables the cat inefficiency codes you'll pass emissions without any issues.

 

Either direction you go, I'd recommend having the manifold and downpipe ceramic coated as an added measure to keep your excess heat in check.

 

Evolve Catless Downpipe in my opinion is the best out there right now in the catless world. Considering it is pretty easy to swap out you can wait on the NM to see if that is what you want or call them and ask if they can give you any details.

 

I have a WMW 2.5in catless downpipe. Really nice build quality and only $299. Getting it ceramic coated is best.

 

You won't regret a catless downpipe. The sound is so entertaining