This is probably obvious to those who know the answer, but I dont want to gut my precats if I need them to pass emissions. So, the question is will my 87 T2 pass emissions with just the main cat? I assume it would, but that brings me to wonder, what was the point of the precats? I know alot of you have tried this so let me know!

 

Well every car will be different. It depends on the condition of the main cat as well as how rich/lean you are running. I believe alot of FCs fail emmissions even with the precats, so I wouldn't assume you will pass.

 

I passed with just the main cat on who different TIIs. One had a DP, and the other had a guttted precat.

 

The precat is only for reduced emissions during warmup. As long as you take it there really hot, you shouldn't have a problem.

 

yeah, make sure you warm that sucker up good before you get tested.

 

Passed Jersey emissions with flying colors. Bonez DP and Bonez hi flow cat. Air pump operating a must.

 

Thanks for the info guys. I looked under my car yesterday and saw how freakin' huge the precats are. Those things must wiegh a ton! Makes me wonder if it is worth the extra money right now to buy a downpipe instead of gutting the precats. Would say alot of wieght! Hummmm.... Think I'll decide that when I get that sucker off and can wiegh it.

 

Not really but a DP will flow much better than a gutter precat. Worth the money as long as boost creep isn't going to be a problem.