Wrong head and intake with B18a1 swap

I recently had to swap in a newer (unblown) B18a1 motor. When I ordered the engine from a Sacramento used parts distributor, AKA wrecking yard, I had asked for a B18a1 for a 1991 integra GS and when it arived at the shop where I had it installed a number of problems came up.
1st, they couldnt use the head on the new engine so they used my old one. (no biggie)
2nd, The CEL has been on ever since the swap. Throwing code 7 and 13.
3rd, After looking at the head and the intake manifold I see why the mechanic said it wouldnt fit.
It seems that the upper engine parts were marked as P75 and the one I’ve always run was a PR4.
Could this be part of the code 13 ? I simply dont have the $$ to have something that I could do at home done for what could amount to a sensor issue.

So why would the bottom block be a B18A1 PR4, and the top parts be from a P75 honda engine? v
Are they compatible? P75 is 1992-93 integra, right?
How would someone with a CEL code 7 & 13 remedy these malfunctions and be about getting this teg smog-ready with no CEL or codes?


As far as I know a p75 head is one from a b18b or a B20b

so it would or would’nt fit on a b18a1?

all b-series are interchangeable. b16, b18, b20. the only diff were small things like the intake on the b18c and the water pump. yes, your pr4 and the p73 are both interchangeable. did you keep the blown motor or did the shop keep it? they could have kept the pr4 because it was a better head. it breaths a lil better and overall makes a lil more horse than the p73.

Wait… P73? Isn’t that a Type R head? I think we were talking about the P75 head which should be from a B18b obd2 or B20 (My b20 came with a P75 head) From what I have read (I could be wrong) the P75 head is better due only to cams than a PR4 from a b18a1 but just about the same as a PR4 from a b18b. So I’m guessing the difference between 90-93 and 94-95 PR4 heads are the cams they use. As far as swapping them out… All B series are interchangeble so you shouldnt have a problem there.

But because I’m not 100% positive, I’m going to post this here