So I got an new infrared thermometer and was taking some readings on my normal operating temperature idling prelude on it's header and observed this:






It seemed like #2 cylinder was always 100F greater than the rest... Does this indicate a problem?

Also, I once had to replace my cat because the inside was melted due to my timing being way off and replaced it with a high flow cat. I took some readings on the down pipe and on the cat. From the header on down I got lowering temps until I got to the cat, heres a picture of the temps I was getting:



Is this little increase normal?

 

Cat looks normal. Swap #2 and #4 injectors and see if #4 runs hot. If so, replace the injector.

 

Knock the rust off of the surface before taking the reading. The rust can affect both the conduction and emmisivity of the surface.