1999 Lexus RX300, 150k mi, Automatic
Throwing codes P0505 and P1135
My partner bought a car without taking it to a mechanic first, fortunately only paid $2k for it. It was running a little rough and check engine light was on, but she managed to drive it 90 miles home without issue. She was told that was because the plugs and coils were just changed, but plugs and coils don't throw air sensor codes.
I haven't touched it yet besides plugging in my bargain scan tool. Should I just start changing out sensors or attempt to clean them? Is this indicative of a bigger problem, or just a 22 year old car acting it's age?
Start with cleaning the throttle body and check for any intake leaks -
https://www.engine-codes.com/p0505_lexus.html
For the oxygen sensor, you can try your luck with a used OEM one from a junkyard or buy a brand new OEM Nippon Denso oxygen sensor -
https://www.engine-codes.com/p1135_lexus.html
If both the codes still appear post doing the above, it may point to a faulty ECM.
All the best!
Don't forget the obvious stuff, air filter, MAF sensor cleaning, etc.
