Debating on changing Exhaust system on my 2017 Chevrolet Tahoe

ANSWER : Hi There,
Adding any kind of performance exhaust system to your vehicle should increase your fuel economy slightly. Some things to consider are also having the computer remapped to account for the change in exhaust flow. This will allow the motor to run smoothly as the change in exhaust flow will impact the way the engine runs and how the oxygen sensors read the fuel and oxygen content coming from the exhaust. As to the warranty, you will need to refer to your local Chevrolet dealer to find out if this will impact the warranty.

ANSWER : As a general rule of vehicle warranty, you cannot modify your vehicle’s exhaust system if it involves any smog-related component, such as catalytic converters, while your vehicle is still under an emissions warranty. Emissions warranties are valid for a longer period of time and for a higher amount of mileage than regular vehicle warranties. Replacing emission control devices with aftermarket upgrades, not service replacements, would void your manufacturer warranty and the cost of repairs would be your responsibility if something were to go wrong.

Some exhaust system components like headers and high-flow catalytic converters can be upgraded if the components have been tested, certified, and approved by the state for use as a replacement emissions control component. Keep in mind that doing so will invalidate the manufacturer’s warranty on those components. It you install these components after the emission control warranty for your vehicle has expired, then you don’t have to worry about voiding the warranty or not.

There are upgrades that you can do to your exhaust system that don’t interfere with emissions warranties. Generally, these upgrades to your exhaust system are referred to as "cat-back" systems because they replace the exhaust system from the back of the catalytic converter to the rear of the vehicle. The catalytic converter is not replaced in this situation.

ANSWER : There are more than ten principal causes of rough idle and that list doesn’t include potential mechanical faults such as uneven cylinder compression. By far, the most efficient strategy to resolve this issue is to request a rough engine idle diagnostic. The responding certified mechanic can scope the cylinder firing patterns, in each cylinder, and see, at a glance, if the problem stems from a few faulty cylinders or if there is a global engine management problem. Among the more notable causes of rough engine idle are a stuck open EGR (exhaust gas recirculation) valve, dirty fuel injectors, incorrect idle speed setting, vacuum leaks, incorrectly installed or damaged spark plugs, defective or clogged fuel pump, clogged fuel filter, failing electronic components such as the ignition control module, plug wires, coils, and spark plugs, a defective airflow sensor, and dirty oxygen sensors.

ANSWER : Hi there. Since you completed so many different repairs, it unfortunately opens the door to multiple possible issues that might be the source of your hard to start issue. The first thing I would do is knock off the easy checks; by verifying that all electrical connections, fuel and / or vacuum lines are correctly attached. If everything checks out there, I would either replace the wiring harness to the crankshaft position sensor or check the output from the PCM. Most of the time when crankshaft position sensor issues exist, it’s the wiring harness itself that is faulty. Try those steps and if you still need a hand diagnosing your problem, feel free to contact one of our mobile mechanics and they can come to your location and complete a car is hard to start inspection.

ANSWER : The windows can be repaired if you request a window regulator/track inspection. For door lock issues, please request door locking system diagnostic/repair. The engine operating condition problem you are having should be diagnosed as a possible misfire although the mechanic would consider a fuller slate of possibilities in order to get to a resolution (i.e., pinpoint the fault). For example, you could have an issue with one or more ignition coils, a sticky fuel injector, the throttle position sensor, a vacuum leak, faulty oxygen sensor, and so forth. If you request the misfire diagnostic, the responding certified mechanic will get this taken care of for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

ANSWER : There are many options on the market today that only a muffler replacement will improve the sound. You can go on some web sites and they will have sounds of the muffler they have for sale to give you an idea of what it will sound like. You can replace just the muffler or the exhaust from the catalyst back to get a more powerful sound. Talk to other owners to see what they used to get ideas for your car.

ANSWER : It seems you have covered the basics and changed the most common culprits for engine vibrations. I will recommend you have an experienced technician inspect the work done and the drivetrain for other problems. In some cases, an improperly installed new engine mount can cause a vibration to stay. Hire one of our experts here at Your Mechanic to inspect the previous work done and diagnose the source of the vibrations.

ANSWER : Hello, thank you for writing in. Typically the catalytic converter does not require that you replace the exhaust manifold. The exhaust manifold refers to the manifold of tubes that connect from each piston, and bring the exhaust together to the main exhaust pipe. The catalytic converter is mounted on the main exhaust pipe further down. If there is a leak at the exhaust manifold gasket, or the manifold is cracked, then it may need to be replaced. With that being said, it may also be part of the reason you are getting bad readings at the oxygen sensors. Our technicians can replace just the catalytic converter, but it may not solve the emissions testing issue if the manifold is leaking. Contact customer service to get a better breakdown and explanation of the estimate.