What is the 7.3 diesel crossover pipe?

The "7.3 diesel crossover pipe" refers to a part found on Ford vehicles equipped with the 7.3L Power Stroke diesel engine, specifically those using a dual-exhaust system. It's a pipe that connects the exhaust manifolds from each bank of cylinders (one on each side of the engine) together, before the exhaust splits into separate pipes leading to the mufflers. Essentially, it's a section of the exhaust system that "crosses over" from one side of the engine to the other.

Its purpose is often to:

* Equalize exhaust flow: Help balance the exhaust pressure between the two banks of cylinders for smoother engine operation.

* Reduce emissions: Contribute to improved exhaust flow and potentially reduced emissions, although this is secondary to its primary purpose.

* Route exhaust: To create a more compact or efficient exhaust path.

It's important to note that not all 7.3L Power Stroke engines had crossover pipes. The presence or absence depends on the specific year, model, and configuration of the vehicle. Therefore, you need to know the specific vehicle year and model to be certain if it has one.