Toyota 4Runner Catalytic Converters

Best Maintenance Practices for the Toyota 4Runner Catalytic Converter

The catalytic converter of your Toyota 4Runner is designed in such a way that the only time you'll do any tinkering is when it breaks down due to wear. And the best way to delay the wearing out of your catcon is to provide it with regular maintenance. Toyota 4Runner catalytic converter maintenance can be quite simple, as it generally revolves around responsible driving practices and constant monitoring. And to help you get started, here are the best practices on how to take care of your SUV's catalytic converters:

• Don't let the engine overheat.

An overheating engine can do more than just shorten its own lifespan. Misfires and premature detonation caused by running the engine at higher-than-normal temperatures will melt the ceramic substrate and matting inside the converter. So once the temp indicator in your dashboard hits the high notes, let the engine cool down immediately. If you find your SUV running hot constantly especially when idling, have the engine and the cooling system checked by a mechanic.

• Replace the engine oil on a regular basis.

Engine oil tends to get foul over time, and when this happens it will cause the valves and piston rings to wear down and allow oil to seep through. The oil will eventually reach the catalytic converter, destroying the catalyst and causing a thick, bluish smoke to come out of the exhaust pipe. The replacement interval of the engine oil in your 4Runner depends on the brand and viscosity of the oil, so make sure to refer to its container for instructions. In addition, if you suspect the engine valves and pistons are leaking oil, have the engine undergo a compression or leak test for a proper diagnosis.

• Keep silicone sealant away.

Silicone sealant is normally used to seal the exhaust manifolds and headers, which tends to burn up when exposed to high temperatures. When this happens, the silicone turns into gas that coats the oxygen sensor, resulting in a condition called "outgassing", which can cause the converter to overheat. To avoid this, do not use silicone sealant or other silicone-based products around the exhaust side of the engine.

Replacing the catalytic converter of the Toyota 4Runner is a task that happens rarely, but it's also something that must not be put off. Designed to minimize the pollutants found in exhaust gas, the catalytic converter is key to maintaining your vehicle's fuel emissions at acceptable levels, so without it, the vehicle will no longer be roadworthy. You can normally have the catalytic converter replaced in an auto repair shop, but this can be quite expensive. So if you have the necessary tools and equipment at home and some experience in replacing auto components, you can save a lot of money by installing the converter yourself. And to help you, here are some key tips you can follow when installing a new Toyota 4Runner catalytic converter:

Tip #1: Get a replacement converter that complies with the emissions laws of your state.

Before you can mount a new catalytic converter in your SUV, make sure it follows the state's emissions laws. A vehicle with the wrong type of catalytic converter will still not be considered street-legal, so you need to do your homework first before you purchase a converter. To determine the right type of converter for your vehicle, you need to refer to the Emissions Control Information Label, which is affixed inside the engine. You should also consult with your state regulations regarding aftermarket replacement converters. California, for instance, has a stricter set of rules for catalytic converters than other states.

Tip #2: Allow the engine to cool down before starting.

It seems obvious but it's worth repeating: the catalytic converter and the surrounding pipes can get extremely hot while the engine is running, so allow them to cool down first before touching them to avoid serious burns. The catalytic converter and pipes should cool down after several minutes, although it's still recommended to wear a pair of heavy mechanic's gloves before working on the exhaust system components.

Tip #3: Remove the bolts properly.

Starting with the bolts at the back of the converter—the ones closest to the open end of the exhaust—will put less strain on the pipes than if you started with the bolts at the front. Make sure to use the right size of wrench to loosen and remove the bolts.