I have a 2009 RA that ive slowly been swapping to evo X parts or better. evo X turbo, evo X header, widemouth DP, 3" highflow cat and 3" all the way back. CBRD intake, running tephramod. and tephramod is setup to run MAP, so my MAF scale isnt a factor.

SO I was on stock injectors, and every time i went above 21 PSI my AFR would climb to 13.x usually only over 4500-5000 RPM. I thought for sure it was my injectors, so i installed FIC 1000cc. I got them pretty close to dialed in, still need to get the trims a tad closer, but im talking about 6-7% off... needs work but the problem is still there where its going lean up top above 21 psi. AFR is rock steady at 19-20psi ive been pulling my hair out trying to see what could be the issue. fuel pump ? stock fuel pump has 148k miles.... I already changed all my relays also.
any guess on what could be causing a lean out up top would be appreciated..

 

check fuel pressure at the rail along with voltage pump is actually seeing just a few tips
along with boost leak up top i had a phantkm boost leak lol on mine it turned out to be a small tiny hole in a vacuum line cant remember which one but it was by the brake booster my car did same thing

 

I actually did have a small leak I fixed and still had an issue. I ended up just replacing the fuel pump out of frustration and as soon as I pulled it apart it made sense. The stock fuel stock with 145k miles was black. I’m surprised the car ran at all. New 340lph pump and fuel sock. It changed my fuel
flow so much I had to retune everything. But all is great now.