I have a 2019 Lexus es 350 with 70k. I had some check engine light and warnings show up on dash today.. I scanned it at auto zone and the codes that came up are: P0174, P117B and P0505. Also, the vehicle is showing parking support brake malfunction warning on dash. Please help. What all can I do myself in order to diagnose and fix this issue.. shops are expensive :/

 

First research the codes like anyone else would, then do your diagnosis. Do the easiest things first. I’d start by looking for a vacuum leak.

 

lean on one bank... injector code.. hmm. plugs good? i like to start with basics first. like what are the basic things you haven't done to the car yet for 70k miles

 

I would clear the codes and see which one(s) return.

 

Vacuum leak, bad injector, clogged air filter.


Clear all the codes and check if they would return.

 

I had this happen to me yesterday, at the gas station after a fill up. My mechanic suggested a new throttle body. What was the fix for your car and did it work?

 

First step is to find new mechanic who can actually diagnose problem. Follow advice already given. Clear codes and see which one comes back first. Sometimes you will see a companion code which has nothing to do with problem.