EGT Probe Placement

[cvp0917]

I know the best place to put an egt probe is in the headers but i dont wanna take them off and drill cause thats a pain in the a$$. anyways, i have an extra o2 sensor bung on the curve of my j pipe and i was curious if anyone has extended their primary o2 sensor to there and placed the probe in the o2 sensor's old spot? like drill and tap the plug from the downpipe. like what could be the downsides and such or should i just put it in the empty o2 bung? is there really that much temp difference? thanks guys!

[BlkZoomZoom]

Egt's should be placed half the diameter of the primary tube from the head. So if you have a 2" primary tube then the egt should be placed 1" from the head surface.

[Mallard]

Egt's should be placed half the diameter of the primary tube from the head. So if you have a 2" primary tube then the egt should be placed 1" from the head surface.
+1

Plus you should have it in cylinder 2 or 3 since the middle cylinders will be hotter then the outside ones. (provided one of your injectors isn't completely fu#ked and you're running lean in one cylinder.)

The temp will be quite different farther down the exhaust.

[cvp0917]

do you guys think moving the o2 sensor like that would be an ok idea for someone who doesnt want to drill the manifold at this time? id end up doing that if i had to take the turbo off say for an exhaust install.

[pdhaudio83]

its not a good idea. the o2 needs to be somewhat close, and the EGT needs to be right in the mani to get accurate readings.

[cvp0917]

ya but its only like a foot and a half farther down the exhaust and its still closer then my primary was on my civic.

[Mallard]

Placing an EGT probe where your primary O2 sensor is in the manifold will give you average of all cylinders and will be a little cooler. The purpose of EGT is to save your engine when timing gets pulled and there is not enough fuel to cool down hot exhaust gasses. Placing the probe as close as possible to the exhaust valve will give you the best indication of how close you are to melting an exhaust valve.

If you're going to do it, do it right. Put it in the runner for cylinder 2 or 3 and ~2" from the head if you actually want to make the gauge useful.

[cvp0917]

alright then. does anyone know if theres enough play in the system to take the header off and still leave the turbo attached to the exhaust and fluid lines and such. i know id have to prop it up but cant it move around enough to get the header on and off?