I have been having this discussion with my car buddies quite often, on reasonably priced but reliable sensors for various functions across platforms, so I thought a sort of "database" with proven sensors for each job might be handy. I know most of it has already been beaten to death, but having it all in one place might be useful.

Oil/coolant temp:
GM-style sensors seem to be the norm here, and they are cheap and reliable

IAT:
Open element GM-style sensors are the consensus for faster response. In harsher conditions, closed element ones (same as the oil/coolant ones) may be used, however their response is slower.

Oil/fuel pressure:
I have seen people recommending both ProSport and eBay specials. I have used KA sensors as well in the past but they ain't cheap.

AFR:
Bosch LSU 4.2 or 4.9 seem to be the norm; the controller might be more important than the sensor itself in this instance

Knock:
For Miatas, OEM NB seems to be good enough. I have used BOSCH "donut-type" non-resonated one in the past (not in a Miata), part no. 0261231006

EGT:

 

Honeywell makes about a billion pressure sensors to cover every price range, port style, and pressure range. Some "race" pressure sensors are rebadged Honeywell units at double the price.

The PX3 series is cheap ($30 range) and is available with an HNBR seal for good fluid compatibility. The MLH series is in the $100 range but has no seal and all stainless wetted parts, giving it nearly infinite fluid compatibility. It is available in both low (good for coolant pressure) and very high (good for brake pressure) pressure ranges, along with typical 0-100psi oil/fuel ranges. It also has a stainless port fitting and a light composite body, making it very mechanically robust to vibration.

 

thesensorconnection.com is my goto for EGT

 

I bought many sensors from https://epsonsupports.net/blog/fix-r...rtridge-epson/ whose built quality was really nice and I am using it till now.