well the other day my car through the p0091 code and ever since had been in reduced power. we deletedthe code but it instantly comes back my fuel pressure sits at 72 and my car barely moves. what do I need to replace I'm running full e85 on zzp cams. also when we deleted the code you can hear the hydraulic fuel pump makes sounds like it's trying to work then shuts off.

 

Make sure it's not this
https://www.cobaltss.net/forums/08-1...-p0091-225564/

Other than that I would guess your high pressure fuel pump took a dump.