Exhaust Gas Temperature Sensor Installation Tips

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The EGT sensor should be placed close to the cylinder head exhaust ports and before the turbocharger. Typically we tap the exhaust manifold with the 1/8 NPT tap and thread the EGT sensor directly into the exhaust manifold. The 1/8 NPT pipe thread seals fine if the exhaust manifold wall is thicker than 0.120" (3mm).  For a thinner exhaust header wall, you may need to weld an additional 1/8 NPT steel bung. We offer steel and stainless steel bungs.
The cast iron exhaust manifold could be drilled and tapped without removing it from the car by carefully drilling then tapping the 1/8 NPT hole while having an assistant rev the engine to 2000-3000 RPM. The turbocharger creates enough back pressure to blow the shavings out.

Be careful! If you try hard enough, the shavings will fall into the exhaust manifold and find their way out through the turbocharger blades or get sucked back into the cylinders and cause a serious damage. If you do not feel comfortable tapping the exhaust headers on the car, remove them!
Drilling the exhaust manifold without removing it from the car may damage the turbocharger or the engine. Do it at your own risk.

Place the EGT wires as far as possible from the ignition components such as plugs, plug wires, and coils. Since the ignition components carry thousands volts they are a very powerful sources of EMI noise. The EMI noise may be inducted into the EGT wires. The Zt-2 has a sophisticated common noise rejection circuit, however the EGT signals are in mili volt levels (0.001V) where the ignition carries tens of thousands (10000) volts and placing the EGT wires near the ignition components may result in false peak EGT readings.

On turbocharged engine the EGT probe should be placed before the turbo.  A high temperature drop occurs across the turbocharger which will throw off any EGT readings taken after a turbo.  This temperature drop is variable and so the preferred EGT probe location is before the turbo.

WARNING!
The EGT probe is subject to an extremely violent high temperature / high pressure environment. Over time it could be possible for an EGT probe to degrade and potentially send fragments into the exhaust system and turbo charger.  The tip of the EGT probe is designed to slowly burn away and EGT probes normally quit working before degrading to a dangerous point.  We have never seen our EGT probe fall apart, never the less we recommend  you periodically inspect the EGT probe for signs of damage.