Code: P2187 help please

[Saint]

Hello.
I was hoping for some help regarding my 2015 fiesta ST.

It threw up the code P2187 (system too lean at idle)

so far I’ve checked for vacuum leaks by using a DIY smoke machine, I plumbed it into the intake but couldn’t find any leaks.
is there another hose I can blow smoke into to check for a leak?

I checked the exhaust for leaks as well. I don’t know how well my method works but I pressurised the exhaust and sprayed soapy water on it to see if I could spot any bubbles but nothing.

next I replaced the MAF sensor with a genuine part but still get the code come back

I have a Foxwell scanner and it showed my long term fuel trims were really high at around 45%

The oxygen sensor output voltage bank 1 sensor 2 is 0.5 volts. Is that what it should be? I’m unsure

I’m not sure what my next plan of attack should be. Any suggestions? I was thinking maybe something fuel related?
actually I can check the fuel rail pressure

I was thinking of checking the in tank fuel pump filter to see if that might be clogged but it’s a bit of a job because the only why to access it is to drop the tank

any help would be greatly appreciated

 

[WannabeST]

How many miles are on your car? Would it be possible one of your injectors is getting clogged?
I would change fuel filter and either throw in some injector cleaner or take the injectors out to clean them.
That would be my plan if I was in your shoes