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Common Mistakes When Installing an Exhaust System

Common Mistakes When Installing an Exhaust System

Jul 9, 2013


We know the feeling—the excitement of opening your new exhaust system, the sense of urgency as you pour the contents of the box on the floor and the dread when you realize that you lost one of the bolts. If this sounds familiar, check out this list of common mistakes when installing an exhaust system. With any luck, some of these experiences from less-fortunate installers will sink in and remind you of what not to do with your new tubes.

Ordering the Wrong Kit

How are you going to install a performance exhaust kit that isn’t designed for your ride? Answer—you aren’t, unless you own a hydraulic mandrel-bending machine, a welder and fabrication skills that put Jesse James to shame. If you’re like the rest of us, it’s easier to research your ride’s engine, chassis and drivetrain options. So, run your ride’s VIN through one of the free VIN decoding sites, open the hood and look at the white, rectangular emissions sticker or if you still can’t find enough information, call your dealer.

Going Too Big

When it comes to exhaust systems, bolting on the biggest pipe possible is a sure way to kill performance. Not only does a cat-back exhaust system have to flow a large volume of exhaust, it needs to flow it out of those tailpipes fast. Sadly, exhaust velocity is commonly overlooked, which is a shame since scavenging effects have a huge impact on horsepower and torque. Basically, the burned exhaust gasses speed through the performance headers, x-pipe, cat-back and tail pipes. This draws additional exhaust out of the cylinders during the exhaust stroke. As a side effect, this creates extra room for incoming fresh air and fuel to enter the combustion chambersto ramp up horspower. All things considered, most rides run better with a kit that’s slightly larger than stock, combined with high-flow mufflers.

Unsafely Lifting Your Ride

We’ve all seen cars mounted on cinder blocks in the front yard of some houses, but this is an unsafe way of securing several tons of metal above your head, and it creates a vehicular booby-trap. While some of us are lucky enough to have an overhead lift, the rest of us have to be content with installing exhaust systems in the driveway. So, start by finding a level spot on a solid surface such as asphalt or concrete. Lift one corner of your ride at a time with a hydraulic or screw-type floor jack. Be sure to place a jack stand under the chassis or frame. And, once your ride is sufficiently up in the air, try to rock it back and forth. If it doesn’t budge, you’re good to go for the next step. If the car moves on the stands, reposition them and try again until your ride is rock-solid. Just remember, allowing your ride to fall on you or your newly-installed ceramic-coated long-tube headers is definitely a bad thing.

Not Allowing the Factory Pipes to Cool

It’s no secret, exhaust systems get incredibly hot, burning anything that contacts them into a crisp. Thankfully there is an easy way to protect you from some serious pain and it’s free—waiting a few hours before starting. Exhaust pipes have a way of suddenly falling off of your ride once you un-bolt them. And, not surprisingly, most of us would prefer to have a cool exhaust pipe fall on us versus a hot one. Simply waiting a few hours for your ride’s pipes to cool is all it takes to prevent painful burns.

Losing Components

Opening a box full of axle-back exhaust system tubing is an exciting thing, but don’t let that excitement make you careless. Curb your enthusiasm until the new kit is bolted on your ride and keep every last nut, bolt and washer organized like the critical component they are. One thing’s for sure, having every component organized vastly simplifies installation. And in case you find one of the new pieces is defective, it’s a good idea to organize the old parts you remove, to make your ride drivable while you wait for the replacement part.

Reusing Non-Reusable Gaskets

The stock gaskets that you pried off of your ride’s catalytic converters are a leak waiting to happen. Designed for a one-time installation, these gaskets compress and seal but will often fall apart when removed. So, install a new set of gaskets, and you won’t have to worry about your brand new exhaust leaking. Even better, while you’re down there, replace those cats with high-flow units and have a good excuse to replace both the gaskets before and after the converters. While most kits come with all of the gaskets you need for installation, there are rare occasions where additional gaskets need to be purchased separately. Understandably, that’s where the temptation to re-use the original gaskets kicks- in. But keep in mind, even minor leaks cause major drivability issues. Just remember, a few extra bucks for a fresh set of gaskets prevent major headaches down the road.

Fully Tightening Mounting Bolts before the Rest of the Kit is Installed

Performance exhaust kits are custom-designed for your ride. That means they only go on one way. It pays to have a bit of clearance to work with as you navigate tail pipes through twists and turns to meet with the correct flange. Sadly, if you cinch up the first exhaust tubing, it leaves you with no wiggle-room to get the next section in place. So, leave each component bolted loosely in place and articulate the tubing sections into place with ease. Once everything lines up, go back through all of the bolts and tighten them to the required torque specification.

Leaving Labels or Plastic Wrap on Exhaust Components

Occasionally, exhaust manufacturers place part number decals on the components to make is easier for them to assemble your kit and ship it out quickly. Also, plastic wrap is used and forms a near-invisible barrier against scratches and damage during shipping. What do they have in common? If you forget to remove them, they melt to the hot exhaust system, smell terrible and leave an ugly, permanent stain on your ride’s shiny pipes. The best way of preventing this from happening is to remove all labels and plastic wrap from the system. The labels are a bear to remove, but a solution of soapy water or a commercial adhesive remover makes this a simple task.

Now Go Install That Exhaust Error Free

Issues with installing an exhaust system are avoided by being informed, cautious, organized and using thorough planning. Like many other mods, the quality of the finished product depends on the amount of care you put into it. And, taking the time to research your ride prevents days of lost time and headaches going through a return process at your expense. Simply spending a few extra minutes to check bolt tightness is enough to prevent leaks that pop-up years down the road. With enough time and care taken, there’s no reason you can’t successfully install a performance exhaust system on your ride too.