So Fix it

The Chevrolet Cavalier might have been a pretty decent little car in itself, but a certain malady followed the name wherever it went. Not only was the Cavalier not quite the import-killer that GM had hoped; older buyers had never forgotten that it was essentially a rebadged relative to the worst rebadged travesty in history: the Cadillac Cimarron. The Cobalt that replaced the Cavalier, free of such burdensome history, rose quickly from its 2004 debut to become one of Americas favorite compact cars.

Dash Lights

The 2008 Cobalt, like most modern cars, used a few different dash bulbs. The basic bulbs were single, white LED units from Equus, part number 9903. Part number 9904 was three 9903 bulbs splined into the same harness. The 5-inch Autometer tachometer uses a white, twist-in bulb, part number 3219. The gauges also use a few Autometer-brand, colored LED bulbs: the green LED is part number 3283, the blue is number 3286 and the red LED number 3294.

Car exhaust systems vary depending on application, piping dimensions and design. Ideally, exhaust piping and components of the correct size provide optimum flow, exhaust velocity and minimal back-pressure. Exhaust size affects power and fuel efficiency, too.

System Components

An exhaust system is broken into multiple components. The exhaust manifold initially routes exhaust into front piping that leads into a catalytic converter. There, carbon monoxide is filtered. From the catalytic converter, exhaust flows into a muffler and out a tailpipe.

Exhaust Flow

The size of exhaust piping directly relates to exhaust flow. Piping that is too small will constrict flow and create excessive back-pressure. A weak exhaust flow reduces engine power and fuel efficiency by forcing engine pistons into firing harder to move the exhaust gases. Large piping increases flow but can reduce velocity.

Exhaust Velocity

The speed exhaust exits the tailpipe is as important as the flow. Slow exhaust velocity increases back-pressure. While overly large exhaust piping allows an open flow, it reduces gas pressure and velocity. The correct exhaust size balances flow and velocity and improving performance.

Back-Pressure

Back-pressure exists in every system that isnt open. Race cars use open systems because they do not adhere to sound or emission laws. Back-pressure forces exhaust back into the engine, reducing performance. Incorrect sizing or piping obstructions cause increased back-pressure.