trouble codes

[geps91stang]

Hey guys I just checked the codes on my 91 and with koeo I got code 22 baro sensor out of range and code 33 egr not opening. Now with koer got codes 41 sysytem running lean and code 91 system running lean for more than 15 seconds. Also when I checked fuel pressure the other day I had just 30lbs with key on engine off. If I have a weak pump causing insufficient fuel pressure will that throw a lean code and will a bad baro sensor cause a lean condition any help would be appreciated.

[geps91stang]

Nobody here has a clue?

[geps91stang]

UPDATE- Went and got new fuel pressure gage and rechecked it turns out the old gage was junk with the new gage I got 38-39lbs with just key on and with engine running I had 35-36 lbs I also had 43 lbs with the vacuum off of the regulator so the pump seems to be working ok. Since I've got a code for the baro sensor out of range im gonna replace it to see if it makes any difference I don't know what else would cause it to run lean