Just wondering on my '94 Z28 Borla Cat-Back, on the highway or at high speeds (70mph+) when I let off the gas and slowly get back on it I get a weird sound coming out my exhaust, almost like a throaty "womp womp womp" for a second then goes away. It'll only happen when Im going pretty fast and sometimes at lower speeds.

Does anyone else have this problem with Borla or is it something I should really look into with my engine?

 

u may be running rich and the leftover fuel is lighing up in the exhaust when u bring the throttle back up. is it backfireing at all when u let up on the throttle.

 

I've run at all grades of gas and it still makes that noise, nope no backfires just that muffled womp noise

 

are u sure its in the exhaust. could it be a drivetrain issue.

 

im pretty sure ur just hearing a mild backfire from running rich if not it could be youre driveshaft thats making the noise look for a worn bearing or major wear and tear on it. . .
how many miles?

 

I'm assuming that, I'm playing this one by ear because I don't have the necessary tools with me at the moment to properly take anything off and look at it...

That's the thing though I've run at 83, 89, and 93 octane and have gotten this through all. There isn't any difference in the noise from grades of gas either..

60k miles...

 

it COULD also be your gears whining

 

Did you install the Borla system or was it on the car when you bought it? If you installed it, did the car make that noise with the old system? If not, that pretty much tells you where the noise is now coming from. You may just be hearing some exhaust "rap" noise due to the more open exhaust. Or does it sound more like a thumping, and do you feel anything on the floor like something may be hitting or vibrating?
You didn't inadvertently opt for the "womp womp womp" feature with the Borla system, did you? That costs more!

 

lol true it might be the exhast hitting under the car lol

 

It was on the car when I bought it, and its made the noise even before I opened it up all the way.
No thumping or vibrating, just the womp womp womp.
Of course not! If I wanted that I could just make the noise myself as I'm driving down the road..."I'm cool WOMP WOMP WOMP...WOMP WOMP WOMP WOMP"