Is there any reason to have an exhaust gas temp sensor vs. an AFR sensor or both for tuning/diagnostics?

is one better than the other for different functions??

It seems i have seen EGT on turbo vehicles more than s/c vehicles.

 

Get both, I remember about a year ago I was reading GM High Tech about tuning they said AFR and EGT are tools you should have for tuning or monitoring N/A or Boost.

 

no, if you had to choose one get the a/f meter for gasoline and egt for diesel. EGT read the heat, and you can be hot from being lean or rich..
If you can afford it get both.
The air/fuel will keep an eye on the overall tuneup. Making sure while cruising and hauling the air/fuel is correct.
The egt will help the turbo live. While driving if you notice egt going up and your a/r is reading ok, then your probably running into boost for to long of a period.

You can have good air fuel and the turbo get overheated. Just from running into boost for long periods of time. This is why alot of diesel guys get the EGT prode, to make sure they are not cooking the turbo.

 

true, i run both but use the egt gauge just to monitor the turbo and make sure im not shutting it down to early with high temps and to watch it while i tow