I just had my car tuned a month or so ago so I'm not in any sort of rush to do it again. I have a Borla catback on and it should be a full 3 inch turbo back. There is a presilencer in there and I think that is preventing some flaming. I am looking for a more aggresive cat back. Would I need to re-tune for this?

 

It depends on what ECU or piggy back you're running, what you power level is, and how restrictive your old exhaust was. There are too many variables for someone to say for sure. I would say at the very least you need to have it checked.

 

You're risking instant-death for your motor, I'd check it just in case. OTOH if you're spitting flames and your boost isn't crazy high then you're probably too rich, which doesn't hurt.

 

Im using an Microtech LT10 as an ecu and last time I was tuned I made 344whp at 15psi. Does this help with anything?

 

Your microtech will be tuned for your current setup and any changes to the car, like exhaust, may have an effect on the way the engine runs. Sounds like you have a nice setup and I think playing russian roulette with the car would be risky. Get it checked and re-tuned as necessary.

 

I think he wants to spit flames and thinks the presilencer is preventing them

 

If the pre-silencer is preventing flames then it is probably restrictive. Opening up the exhaust can cause the car to run leaner than intended. There are too many variables to say what it will do for sure which is why it needs to be checked and re-tuned as necessary.

 

If you have a wideband, I'd replace the exhaust and see what kind of a difference it makes. If nothing changes, or get .1 leaner or richer, I probably wouldn't worry about it. If you go from running 12:1 to 15:1, I'd probably worry about it.

 

you should always have it tuned

 

that's the nature of a standalone. Get it tuned, or learn how to do it yourself.