Engine Malfunction P1209 code came back.

[Adriano917]

Long story short, I installed a S/C and everything went smooth with no CEL whatsoever and running great. Drove the car a few times to put 150 miles on it and no problems, had a shop install some resonators to quiet the car down and when I picked it up the CEL was on and on limp mode (coincidence), I keep a scanner on the car just in case and got the P1209 code(brake booster, vacuum sensor) fault. Replaced the vacuum sensor since its the most common and no dice the code came back after driving back from work yesterday, I’m gonna buy some brake cleaner and spray vacuum hoses to see if I don’t have a leak, but I’m thinking it might just be the vacuum pressure pump itself. Anybody know what the fuse is to check the ELUP ? Any advice ?

[Adriano917]

Well I checked the fuses #67 & #69 amongst other ones and also vacuum hoses. Time to check the Brake Booster Pump.

[Adriano917]

I sprayed vacuum hoses with brake cleaner and idle never went up, I can hear the vacuum pump on start up a few times intermittently and when I step on the brake.

[Adriano917]

Update : Vacuum hoses were smoked and no leaks, system was holding vacuum properly, brake booster vacuum pressure pump was “working” but not sufficient to normal standards. End result brake booster vacuum pump was replaced and the car is happy and working properly. For future reference if anybody has the same issue and you already replaced the vacuum pressure sensor, checked fuses for the ELUP, no leaks on vacuum system, and you can hear the vacuum pressure pump working, it just might be the pump not working as it should from factory.