All the repetitive post have led me to write this post up. Long time forum participants have seen the same post over and over, and many can not give excellent recommendations. However newcomers could use a resource to help them evaluate their issues and get to the source of the problem or perhaps a new wrinkle to the collective experience of the group, so I thought I would write a primer as first step in troubleshooting issues in D2 ownership (or any vehicle or thing really).

Most good troubleshooting starts with thinking through the problem analysis logically. Compare with you know the truck is doing, versus what it is not doing and use that to formulate a theory about what could be going wrong. Is versus is not. Examples:

It is overheating at idle, it is not overheating on the highway.
It is misfiring under load, it is not missing while idling.
It is throwing a lean code when I drive it on the highway, it is not throwing a lean code if I only drive it in town.
It is misfiring on cylinder number 6 but not number 5 (what is common/not common between them).

Now, once you have some good is/is not facts clarified, you can think through what could be the possible causes. Then, think of ways to test those possible causes to determine if your theory might be correct. One of the best ways to test a possible root cause is to replace known good with suspected bad. Do know assume a new part is good, with the deterioration in aftermarket automotive part quality the last few years many of us have experience a wide range of both mechanical and electronic parts that were defective when new. Lots of people have thrown the credit card tool at a truck with problems spending signifcant sums of time and money before going through a methodical troubleshoot and test process that is much more cost and time efficient.

On a multi-cylinder V8 engine one of the best sources of a known good part can be a different cylinder or a different bank of the engine. Swap the known good part (spark plug from number 5 cylinder that is not misfiring with spark plug from number 6 cylinder for example).

For misfire troubleshooting, the best rule of thumb is easiest first. So that typically means these parts in this order: spark plugs, spark plug wires, ignition coils, fuel injectors.

Other left/right swaps can be oxygen sensors, knock sensors, abs wheel sensors, and even rocker shafts/arms if you suspected something.

Many of us have more than one D2 - perfect source for known good part if there is only one (MAF sensor, Ckps, throttle body, vapor purge valve, etc).

Other times you can disconnect a sensor and see if the behavior changes - unplug the maf, or the oxygen sensor, or the vapor purge valve, or ....

Depending on the suspected part you might be able to monitor a data stream or activation condition in a scanner. Or perhaps test voltage at the part?

Of course it is very unlikely you are the first one experiencing whatever problem you have, that is why you are here in the first place. But before posting your new to you issue, first do a search on past forums and see what others have experience, and then consider crafting a logical troubleshooting process plan to walk through. Feel free to run the plan by the forum members in a post on your problem, they will help you tune the plan to solve the problem as fast and cost efficiently as possible.

Hope this helps some folks our there and improves our overall content here building our share knowledge base.

Cheers,

Extinct