Toyota FJ Cruiser Forum banner
  • Hey everyone! Enter your ride HERE to be a part of JULY's Ride of the Month Challenge!
1 - 6 of 6 Posts

·
Registered
2013 FJ Cruiser Black
Joined
·
91 Posts
Discussion Starter · #1 ·
My FJ is a 2013 with 122k miles. OK I've tried just about everything I could think of and what I could find on the fourm. I had a code P0430 so I decided to replace all o2 sensors because if one is going they might all be going and I should get it out of the way. I also decided to replace the spark plugs. I used Denso on both the plugs and sensors. I was still getting the P0430 code so I decided to add o2 sensor spacers.

Now the only issue I'm having is my bank 2 sensor 2 is P0156 and P0157. I've tried another new sensor, spraying starter fluid around vacuum hoses and air injection pipe, with the o2 spacer and without but nothing seems to work.

Does anyone have any idea why this is happening or something else I could try?
 

·
Premium Member
Joined
·
565 Posts
Check for exhaust leaks between engine and muffler. an error code does not mean the sensor is bad it is saying something else is causing it to give out of spec readings. a leak between the 2 sets of cats will cause them codes, wore out doughnuts, after market exhaust with clamps instead of welded will cause it also
 

·
Registered
Joined
·
5,594 Posts
Bank-2 Sensor-2 is the downstream oxygen sensor behind the catalytic converter on the driver's side.

P0156 definition: Heated Oxygen Sensor Circuit Malfunction Bank 2 Sensor 2
P0157 definition:
O2 Sensor Circuit Low Bank 2 Sensor 2

Questions:
1) Please confirm, you replaced BOTH fuel-air (upstream) sensors and BOTH oxygen (downstream) sensors?
2) All four sensors were Denso OEM identical parts that came with the connector already installed, and not Denso 'universal' sensors?

Suggestions:
1) De-mate the connectors at all four sensors and inspect for corroded or physically damaged contacts.
2) Meticulously inspect for any damage to the insulation on the wires on the sensors and in the wiring harness. Look also for rodent chewing damage on all parts of the wiring harness, including in the engine bay.
3) Inspect the Bank-2 exhaust system for any signs of leakage, starting at the exhaust manifold and working down to the muffler.
 

·
Registered
2013 FJ Cruiser Black
Joined
·
91 Posts
Discussion Starter · #4 ·
Glenarch, sounds easier said than done. It's gonna be tough looking for a leak in such a tight space. Any tips?

FJ Test, I replaced the 2 downstream sensors with Denso OEM sensors that weren't universal. The only codes I was getting was P0430. I decided to change all the sensors. I couldn't get the upstream ones out so I took it to Toyota. Still getting the P0430 code so I added O2 spacers to the downstream sensors. Now the only codes I get are the P0156,0157.

I'll get under there tomorrow and see if I can find a leak or if it's the connection. I have an inspection camera that I think will help.
 

·
Registered
Joined
·
5,594 Posts
Glenarch, sounds easier said than done. It's gonna be tough looking for a leak in such a tight space. Any tips?

FJ Test, I replaced the 2 downstream sensors with Denso OEM sensors that weren't universal. The only codes I was getting was P0430. I decided to change all the sensors. I couldn't get the upstream ones out so I took it to Toyota. Still getting the P0430 code so I added O2 spacers to the downstream sensors. Now the only codes I get are the P0156,0157.

I'll get under there tomorrow and see if I can find a leak or if it's the connection. I have an inspection camera that I think will help.
1st level of inspection for exhaust leaks is visual, and your inspection camera (USB 'endoscope?) taped to a dowel might help get into tight spots.

2nd level is a few feet of 1/4" dia copper or aluminum tubing connected to a few feet of flexible 1/4" plastic tubing and used as an acoustic 'sniffer' to listen for leakage. Having someone blip the throttle might help, but a leak large enough to affect oxygen sensor readings should be fairly apparent.
 

·
Registered
2013 FJ Cruiser Black
Joined
·
91 Posts
Discussion Starter · #6 ·
1st level of inspection for exhaust leaks is visual, and your inspection camera (USB 'endoscope?) taped to a dowel might help get into tight spots.

2nd level is a few feet of 1/4" dia copper or aluminum tubing connected to a few feet of flexible 1/4" plastic tubing and used as an acoustic 'sniffer' to listen for leakage. Having someone blip the throttle might help, but a leak large enough to affect oxygen sensor readings should be fairly apparent.
Thanks I'll give it a shot. My inspection camera is from Harbor Freight Tools. I use it to inspect cylinders, it works pretty good.
 
1 - 6 of 6 Posts
Top