Throttle and idle issue after Legato Exhaust install

[SS2camaro]

Thank you for taking the time to read this message and any help would be a big appreciated!!

I have a bone stock 2015 2SS Camaro with 2000 miles, I recently had a Legato axle back exhaust sytem installed. From the minute it came off rack at shop I've noticed sluggish idle response in the low rpm range (during cornering and trying to get back on gas) and sometimes a ruff idle. Before the install I never had these issues car always responded soon as I pressed accelerator. My question is this a normal? My friend has same car stock also other than he went with competitor sytem and I drove it and he didn't have any delay. Long story short I contacted legato customer support to see what they thought. They said its not there exhaust and asked if I deleted any other parts (which I did not) , I had professional muffler shop put it on per Legato instructions. While waiting for response from customer service I took car to dealership since it's under warranty they did full check on car and was told car was perfect. They did test drive vehicle and suggested I put back on my factory mufflers was told I either have a defective sytem or its not made for my car. I do not want to put factory system back on this vehicle after cutting it out can someone please suggest what they think issue is please. I did buy a K/n cold air intake but I have yet to put it on before I figure this issue out.

[JusticePete]

Great choice to not install anything else until the current problem is sorted out.

I looked over their site. It is chambered so you would think very low back pressure. Time to check for restrictions. Put your hands on the tips and block the exhaust to feel the pressure. Is it the same side to side or is there a noticeable difference?

[SS2camaro]

I have not tried this yet, I'll be with car when I get off and I will check. thank you

[hawk02]

I know this sounds crazy but you might verify that your muffler shop removed the plastic shipping plugs.

[JusticePete]

Originally Posted by hawk02

I know this sounds crazy but you might verify that your muffler shop removed the plastic shipping plugs.

My thought exactly and why I asked him to feel the pressure at the tip. Great minds thinking alike.

[LT1Zob]

Originally Posted by hawk02

I know this sounds crazy but you might verify that your muffler shop removed the plastic shipping plugs.

Not crazy at all. Just a couple weeks back, someone here was complaining about a z28 CAI intake tube collapsing. Turned out they forgot to remove the big, red plastic cap that says "Remove Before Installing"

[SS2camaro]

I apologize about late response been long last week. I covered my hands over exhaust at idle and at load and the flow felt same. Car continues to be same now if I'm changing speeds and let the tack below 2 the car has a missing sound and throttle response sluggish when I try get back on it and going up hill if I let off gas and tack drops below 2 it's even worse and I even heard a small back fire first time hearing that. It depressing adding something to your car that suppose to help cause so much problems. Should I just cut this off and go with a different axleback system? I've tried multiple time to communicate with Legato customer support after 5 emails I've only had the one response not great customer service this far. Hopefully they can make this convenient and send me new ones and I can just send these back. Any other ideas would be appreciated. I do have this CAI I can put on car see if that fixes problem but I didn't want to till I knew what was going on. Thank you for taking time read this.

[SS2camaro]

Yes I made sure I watched him take both plugs out when he did install at shop.

[davidscamaro]

Did you rev the piss out of the car to hear the new mufflers after the install? Could of done some damage by hard reving a cold motor out of gear

[Olddudesrule]

Well, I'd suggest you start with the simple things, even if they aren't related to the exhaust install. Check the intake for blockage, spark plugs boots for fit, plugs themselves for tightness, and work your way down stream from there. If it was running fine before the install, most likely it's something simple...

Good luck and let us know.

[SS2camaro]

No hard reving I've barely done a few but outs with car. I'll start with the list of things you mentioned tonight when I get home see if I can eliminate the easy fixes and keep you posted.

[acammer]

The little backfire sounds like it might just be the typical deceleration sounds you'd expect to be heightened with a louder exhaust. Same with the imperfections in the idle - a stock exhaust will mask those but a aftermarket exhaust will let you hear more of that.

If the exhaust was plugged somewhere the problem would worsen with load/rpm. If it pulls strongly through first gear to the red-line with your foot to the wood then I don't suspect it's a plugged exhaust. If the shipping plug was still in place then you'd have a hard time getting rpm out of the car even under light load - and things would sound pretty weird.

Is the exhaust clamped or welded in? If you're convinced the cat-back did then, and it's clamped in, then loosen the clamps and drop the exhaust - just tie it up for a test drive, and validate the condition is gone or persists. (It's gonna be LOUD!) It's hard to imagine a catback causing such trouble. You should be able to run open-header after the rear cats without a problem, so the freer flowing isn't a concern, just a potential blockage.

[SS2camaro]

It is clamped on Instructions said use provided clamps. I was thinking about doing that taking them off and driving it see if there's still sluggishness in the low rom range .Took this Sunday and went one by one on everything spark plugs/wires. Air intake box throttle body connections air filters checked for dirt ect everything is perfect. I'm at a loss and Legato customer service has still yet to respond to the multiple emails since the first one where they said "it's not our exhaust" which I'm very displeased I honestly made my purchase from them due to this forum and some reviews I was looking for an adult sound not to radical with no drone and it did live up to that no doubt. But when u have a 40k car with 2900miles and it runs like sh%t it's pretty depressing. I'm coming down to its wrong exhaust for my car or its defective. I'm at point where I'm out of ideas and I'm gonna have to buy different sytem and trash this one. I hope a rep for legato would contact me by email or on here and help me through this.

[JusticePete]

I suggest you take a scenic drive and come to see us ;-)

Bring your factory exhaust with you.