Glenn

It doesn't, but tuning for ultra low emissions may result in "driveability" shortcomings, such as stuttering/hesitation.

ULEV, is exactly the problem. This is why the issue doesn't exist on the WRX & the STI. The STI is tier1, & the WRX is LEV. Both don not have the pre-catylitic coverter in the up-pipe as in our cars, unless you remove it like I did.

Can you cite where you found that law?

Regardless, the pre cat doesn't have any affect on emissions. As a matter of fact the WRX STI doesn't even have a pre cat nor do most vehicles under 4000lbs that are turbo charged.

Can you cite where you found that law?

Per the EPA, which I confirmed in NY, PA, NJ & CT so far.

Oh really? Please back that statement up.

 

<----- PGT has smog check coming up in VA soon

In any state where there is a smog check if your vehicle has 50K or higher you are exempt from having anything more than 1 required cat, only exception is diesel where not cat is required.

Did you have your service department call the SOA tech line?

This is not an ECU issue. I had a catless uppie installed, & studdering is gone. Obviously it has to do with the restriction being to close to the turbo charger. Unless, yor're in California where they check for smog emissions, removing this pre-cat isn't illegal.