Blocked cat or blocked fuel filter show similar kind of symptoms. As said fuel filter is relatively cheap to change over but cat you can test by getting it up in the air and using an IR temp gun to check the temperature its getting up to. If you can't do that, check to see how well the exhaust is blowing whilst someone revs it.

If it revs lethargically or has a flat spot then it is definitely something like fuel filter or possible lambdas and/or cat needs looking at. Temperature probe shouldn't have much to do with the issues you are describing.