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I just installed a new catback system. It was fine, then in autoshop I ended up tack-welding some parts.
After I lowered it and started to drive off, there was a rumble under the drivers side where the pedals are. It usually starts around 1500-2500 rpm, its a mixture between some grumbling/rumbling sound with pulsating of the breaks and the gas pedal. I have an automatic. Does anyone know whats causing this?
I remember reading about a recall on civics and their exhausts systems, and it causing problems. Would replacing piping mess up some sort of alignment?
It feels like there is extra weight or pressure on the left (drivers) side, or its rubbing against something (sounds like a big heavy door opening without oil). The sound happens on and off, more on than off now, and on stop and go city driving, it is unavoidable. This happend a few days ago and I havent checked it out with any dealership/carmechanic or some sort. what should I do and what do you think the problem is?

Help would be appreciated

Bboysushi

 
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nvm, just found a huge *** thread about this.
I was confused because it happens when its not even raining.
Ill check my piping soon!

Bboysushi