Is it safe to run a D16Y8 with a busted out cat? Ive got a 00 civic ex with a AEM v2 CAI,DC sports 421 header,busted cat, and 2.5inch catback exhaust? I had JET custom tune my ECU for the modifications i have listed but my check engine light is constantly on? Is it safe to run it like this or is this bad for my engine. I know DOHC run well without a cat but i wasnt sure if the SOHC did as well. Thanks

 

you should put a cat back on, high flow or stock, you will lose a lot of low end torque and you car will sound and smell like ****, it will also get rid of your check engine light

 

You should be fine. That CEL is because the second o2 sensor isn't getting the proper readings. But your A/F ratio should be okay.

Get an OBD reader and make sure that's the only CEL you're throwing. You can get an o2 sim to clear that CEL, because if another problem comes up that would throw a CEL, you wouldn't know.

Or just replace the cat.

 

you're gunna be runnin rich until you fix that CEL. Do motha earth a favor and just put in a real high flow cat, not an imitation test pipe! you only have a D series, you'll need all the torque you can get! With that i'd also step down to a 2 1/4 exhaust but if you have 2.5 just keep it on.