2003 Toyota Highlander Standard V6 with engine code P0135 and P0155

Question

I would like to fix this on my own rather than pay the dealer. The trouble code in order is P0135 and P0155. I hope the first one will correct the second one.

Answer 1

check the relay first

if the issue is still there replace the oxygen sensors

p0135 replace the oxygen sensor on Bank 1 Sensor 1 (in the back of the engine on the exhaust manifold.)

p0155 replace the oxygen sensor on Bank 2 Sensor 1 (in the front of the engine on the exhaust manifold.

 

 

Answer 2

P0135 Toyota Code - Heated Oxygen Sensor Heater Circuit Malfunction Bank 1 Sensor 1
Read more: https://www.autocodes.com/p0135_toyota.html

P0155 Toyota Code - O2 Sensor Heater Circuit Bank 2 Sensor 1
Read more: https://www.autocodes.com/p0155_toyota.html