Pyrometer reading low
 

Pyro ga. is reading low, Normal running 200-300, under heavy pull 400-450.

Automeater ga.,,Would it be the ga. or the sender? Are the replaceble separately? '99 F350 7.3PSD

Do you have the probe in the driver side exhaust manifold or where do you have it?

x2^^^ where it is makes some differences.
but 500 sound like it is in the down pipe.:(

Have it in the down pipe. Temp in past would read 800-900 on hard pull.

I would put the probe in the drivers side exhaust manifold or leave that one on the DP and put another gauge from the manifold.

My probe was in the down pipe. I moved it to the drivers side manifold and the temps went up about 200 degrees. 70 mph unloaded probe in down pipe ran 500-600 degrees. 70 mph unloaded probe in manifold 600-700 degrees.

To answer your question, it looks like you can get just the sending unit, but you'll have to check with your specific model. I just googled autometer pyrometer sending unit and the first few links had just the sender. They looked pretty steep, so it may help just to get the kit and replace it all. As far as which is bad, I'm sure you could find a way to check with an ohm meter to see if the resistance is right. It just depends on which model.

But like it was stated above, the DP isn't the best location, so if you have to order a new one, I'd leave the old probe where it is and drill tap the new in the manifold.

Oofda... bare minimum on the level at 65 MPH (empty) with the sensor in the exhaust manifold is 525 degrees. Jumake-a-me nervous with that 800/900 degree reading after the turbo. Ever felt an air compressor tank when running? Warm. Ever touch the open air nozzle? Cold. The pressure drop always cools things down pretty dramatically.

A bad sensor could read low temp, but I wonder about winter with all that cooling down. I notice my EGTs are running a little cooler straight off the engine (with the heavy-huffing 38R) and I imagine a cold blast on the downpipe would cool your breath.

The location of sensor has nothing to do with what the gauge was reading and to what the gauge is reading now. Same location both times, just was not reading up to par!
Gave a shout out to Cory at Autometer, and he replied with suggestions. My problem ended up being my ground wire(at the firewall) not making good contact. Cleaned and reconnected, and we are good to go again.

autometer needs to keep Cory around, he seams to be running the whole show there by himself.

Glad to hear you resolved it, but move the sensor to the manifold. It's not doing you any good in the downpipe. With the sensor there by the time you read any dangerous temps it will already be too late.