what to check first,second,etc

Question

Whats the most common cause of hesitation, complete loss of brake boost vacuum and code P0300

Answer 1

P1349 (bank1) could be caused by variable valve timing solenoid being dirty or your low is low. Which could cause a P0300 which is a multiple cyclinder misfire which can cause loss of vacuum to the brake booster. 

You might be able to remove the the solenoid (it is near cylinder head near the firewall side) and clean it and/or replace the filter inside

Possible causes:

- Dirty or low engine oil

- Valve timing

- Oil control valve

- Variable Valve Timing controller assembly

- Engine Control Module (ECM)