I am planning on buying a used BMW 318i automatic (the shape from mid 1999). I have seen a lot of cheap ones but with high mileage (100k +). I just wondered how many more miles before the autogear box packs up or needs serious attention. Thanks.

It took the Clean Air Act to help make passenger cars cleaner. Under the Nixon Administration, the Environmental Protection Agency (EPA) was formed in a bid to help reduce pollution and set standards on vehicle emissions with various legislation passed or amended to bring that about. To that end, beginning in 1975 car manufacturers began to install catalytic converters in a bid to reduce pollution, one of the most important parts related to your vehicle’s exhaust system.

Every car engine produces gases which if left untreated can be harmful to the environment. Other than a pure electric vehicle, no passenger car is one hundred percent free of emissions, but some come pretty darn close. Even with all of the modern exhaust systems and engines in place, every car pollutes to some extent.

How Your Catalytic Converter Works

Your vehicle’s catalytic converter can be found on its exhaust line inserted between the exhaust manifold and the muffler. Pellets inside the converter work to alter damaging gases into innocuous gases before they leave the tailpipe for open air. Quality standards are lowered if a catalytic converter is damaged or broken, requiring replacement as soon as possible. States with strict emissions testing will fail any car without a functioning catalytic converter in place.

There are four revealing signs which signal when a catalytic converter will soon give out. They are:

Rusted or damaged converter body or end tubes. Bits of substrate (matter) found in other sections of the exhaust system. No rattle detected in a pellitized converter (If the converter doesn’t rattle, the pellets may have melted and blended together or perhaps fallen out). A rattle detected in a monolithic converter (A rattle in this kind of converter indicates the substrate has separated.)

Change Your Broken Or Damaged Catalytic Converter

If you see hear or see evidence of any of these signs, then you should change your catalytic converter immediately.

I want a smaller pulley for the supercharger on my 1996 bonneville ssei and was wondering if any other upgrades will be needed before doing so in order to avoid destroying my car.

How to reset dashboard warning light on a 2004 bmw x3 after replacing the turn signal bulb after it was burned out?