Hi All - I’ve searched and found no concrete answer around the Uprev platform, but my question to you more knowledgeable folks is this:

I will be swapping my current catless setup (ART pipes) for a set of HFCs (likely ART HFC) - and will that change warrant a retune?

My understanding from researching at a broader level is:
- Catless tunes tend to be slightly richer, which could cause premature wear on cats. True?
- Some tuning platforms have something called COT? Something to down with Catless vs catted exhausts?
- Others (on other vehicle platforms) say they switch back and forth between Catless to catted for track/street with no issues.

If some of the more experienced Uprev experts could chime in, it would be much appreciated.

Thanks!

Edit: 2007 350Z w/ DC Shorty Headers, ART Catless, Shockwave, Z1 2.5” CAI.

 

Ideally I would want to retune, but you could probably get away without if you didn't want to. Bigger issue is if you have emissions testing required and the previous guy disabled any emissions related codes...

 

No emissions testing where I live, but going catted for autocross classing and general environmental well-being.

If the previous tuner did disable emissions codes, are you just saying that would cause an issue with an OBDII inspection? Or something with the health of the vehicle?

 

You would fail the OBD2 scan