I got myself a DTC today - P2188 an

I got myself a DTC today - P2188 and I noticed the engine compartment is quite hotter than one would expect it's like overheating but my temperature gauge within reasonable range i.e. below half of the gauge. Last week we put in a bottle of fuel system cleaner and I suspect this might be causing the problem - can this be true?

If not, I've read from the internet from limited responses that this can range from an intake manifold leak, dirty/busted fuel injector to MAF malfunction/dirt. Any other ideas where to look at?

My first step was to dilute the remaining fuel (below half) with more fuel of lower rating as suggested by a mechanic and reset the code to see if it would come back.

Appreciate any ideas :-)