Before going into a catalytic converter cleaner, inspect it for clogging, internal component damage, and poor fuel economy.
If you’ve recently attempted to have your emissions inspection and was told the car failed, it’s quite possible the root source is a clogged or dirty catalytic converter. The catalytic converter is an emissions-regulated part installed within the vehicle’s exhaust system. It takes out particulate matter and other harmful emissions prior to exiting the tailpipe. Eventually, this component will become clogged with excessive carbon buildup and will need cleaning or replacement. However, cleaning your catalytic converter is not as easy as you may think. In fact, it’s not even recommended by professional mechanics or a car manufacturer and if done, may even void car warranties.
If you’re having issues with a catalytic converter and are considering cleaning it, first determine the cause of the emissions issue. Then, decide whether to clean or change the catalytic converter.
Know the Root Source of Your Failed Emissions Test
90 percent of the time a failed emissions test is incorrectly diagnosed at an inspection point. An emissions test will download the stored OBD-II trouble codes that might seem related to the failed test. Most of the time, the code found is P-0420 — a generic code showing that the Catalyst System Efficiency is “Below the Threshold.” While most of the time this can be added to a clogged catalytic converter, it can equally indicate a failure of one of the multiple oxygen sensors, an exhaust system crack, or about a half-dozen different car problems. If the catalytic converter is the issue, the majority of the time it is past the point of cleaning and need replacement.
If you’re attempting to diagnose the source of this code, you should begin by checking the catalytic converter first. Here are three items to verify before attempting to clean the catalytic converter.
- Know if it’s too clogged:If the catalytic converter is too clogged with excessive carbon deposits, the engine may not work. To check the inner catalytic converter, it has to be removed first.
- Check for damaged internal components:If the catalytic converter is the source of your issue, inner components will be loose or damaged in most cases. One quick way of checking it is lightly tapping the catalytic converter with a hammer and listening for any rattling sounds. These noises indicate damage and need replacement.
- Inspect for excessive oil consumption:Another leading source of a damaged catalyst is excessive oil consumption. This is often caused by damaged piston rings, cylinder head valve guides, or fuel injectors. If you observe smoke coming from your exhaust pipe, this is likely the issue. Cleaning the catalytic converter will not resolve the issue.
Consider Removal and Manual Cleaning, or Replacement
Once you’ve determined that the catalytic converter is not damaged or too clogged for cleaning, the next step would be to remove it and attempt to clean it manually. The best method is using water and lacquer thinner. However, there is no proven step or process for cleaning the catalytic converter this way, so you
As was noted at the beginning of this article, cleaning a catalytic converter is not recommended by any car manufacturer. It can damage the internal catalyst and render this mandated system completely useless. The best solution is to have a professional mechanic change the catalytic converter.