The catalytic converter is a passive after-treatment device designed to reduce engine-out emission levels to meet an acceptable standard. Together with the Oxygen Sensors and other Engine Management Components, this emissions system works to reduce harmful emissions at the tail pipe.
     The catalytic converter contains two or more ceramic substrates, coated with a combination of Platinum, Palladium and Rhodium and a Ceria based wash coat, packed into a stainless steel housing. When placed in the right environment of heat (400°C) and proper air/fuel mixture the catalyst forces a chemical reaction reducing toxic gasses to less harmful ones.

    Catalytic converters rarely fail on their own. Late model vehicles have factory catalytic converters that have warranties for four-years and 80,000 miles. That doesn't mean your newer vehicle won't have a converter problem, but if it does than it's a sure sign that there is something else wrong with the vehicle. The diagram below gives a few examples of what your failed converter may look like, and each example is the result of a different problem. A converter that has overheated is often the result of improper fuel mixture. If the outside of your converter looks like this, then it's likely that the catalyst in side has melted (see #4).A converter with carbon deposits is caused by contaminates in the fuel system such as antifreeze, oil, or even bad fuel. A broken catalyst can occur when road debris strikes the converter body, or if the exhaust on your vehicle is rattling (due to a broken hanger) it can shake the catalyst apart. Once your converter has been replaced you need to find out what caused it to go wrong IMMEDIATLEY. Otherwise it could void the warranty on your new converter.

   Here is a list of symptoms that can help you determine if your Catalytic Converter is bad. You may be experiencing one or more of these symptoms:
Check Engine Light: if you have your vehicle scanned the error code may say P420, which is catalyst failure. The code may vary on different makes and models.

Poor vehicle performance such as hesitation and slower speeds. This means the converter is plugged and blocking the exhaust flow.

A dramatic decrease in fuel mileage. If the converter is plugged your car will have poor fuel economy.

Rattling noises may occur if the converter brick is broken. You need to take care of this immediately because the broken pieces can get in your muffler and require a muffler replacement.

Failed Emissions test. This seems obvious, but older vehicles that passed emissions a few years back are now failing because their converters don't meet standards anymore. See the OBDI and OBDII section.

    Some emission centers suggest dealer or CARB certified converters, but The state of Colorado approves the use of aftermarket converters, but only if it is the right one! Many shops have a use what fits mentality, whereas we use the right converter for the job. Emission centers have the same converter catalogs we do and they check to see if the converter part number installed on your vehicle is the same as what the catalog shows. If your part number doesn't match up, then you will fail. Even if your car passed the tail pipe test. It wasn't always this tough, but our state is constantly making emission standards stricter, and many shops aren't up to date. At Mountain Muffler we do our homework so you can be confident for your emission test.

    Absolutely not! A shop that takes a converter out without replacing it can be fined thousands of dollars. Not only that, but if you go to the emission center without one, then you will fail automatically.

    If your car is built before the model year 1996, then you have what is designated as an OBDI emissions vehicle. That means you have one oxygen sensor monitoring your converter. In the past, cheap aftermarket converters were more than enough to pass emissions, but today we are seeing the old cars fail because standards have risen. When you bring your vehicle in, we will discuss the best solution for your converter problem.

    If your car is built after the model year 1996, then you have what is designated as an OBDII emissions vehicle. That means you have two oxygen sensor monitoring your converter. These cars require aftermarket converters with more precious metal content in order to turn off the check engine light. When you bring your vehicle in, we will discuss the best solution for your converter problem.

   Most auto repair shops don't know that there are subcategories for OBDII vehicles that require special catalytic converters. If you have a low emission vehicle your emission code is LEV, ULEV, SULEV, NLEV, or TLEV. These codes, found on your emissions sticker under the hood, mean your car is compliant to Tier 2 EPA regulations. This means you need a higher grade converter. Don't worry, we can install those for you!

   Yes and No. If you own a vehicle with a model year newer than 2005, then you run the risk of turning on the check engine light if you mess with the catalytic converters. The Environmental Protection Agency has outlawed modifying the original design of your vehicle's converter system. We would not recommend changing your converter unless it has failed. This being said, there are some aftermarket performance converters that will work on certain vehicles while still complying with emission regulations. Give us a call to find out if your vehicle qualifies.

   The catalytic converter market is more complex than ever, complements of the Environmental Protection Agency. We won't turn you away if you bring your own converter, but we will not warranty it either.