Hey Mudders,
I've searched quite a bit for similar posts to my issue, but I cant seem to find anything that helps explain what I'm experiencing. I'm hoping someone can point me in the right direction or has had a similar issue they were able to fix.
The P0135 error is intermittent and can trigger right upon turnover after a cold start, following a hot start, randomly while driving, and often times will remain off for 2-3 starts and many miles of driving. It's HOT and humid in Lincoln, Nebraska right now (95-103 every day with +80% humidity).
Background: 1996 Lexus LX450 - stock other than deleted cats.
Installation:
To wire in the new sensor, I disconnected the upstream sensor from the grey factory molex plug and then cut the wires right at the end of the original sensor so I had an OEM pigtail. I then took the new sensor and wired it to the OEM pigtail so I could reuse the OEM molex connector. The new sensor came with an interesting rewire connector assembly which creates a waterproof seal between the connections of the OEM wiring and the new sensor wiring.
YES, I triple-checked to make sure I rewired the new sensor correctly, and YES I checked the heater circuit for continuity/ohms from the OEM molex plug connections through the rewiring assembly to make sure I wired it correctly.
I installed the new sensor into a new hole I drilled into the exhaust because the old sensor was completely rusted in place (i sealed the small air-gaps around the flange for the new sensor placement so there wouldn't be any exhaust leaks). I filled the OEM molex connector with dielectric grease before reconnecting it and zip-tied the excess wiring/connector assembly from the new sensor to the frame.
I'm not sure if these screenshots help at all, but here are the before and after numbers coming from my o2 circuit while driving around at operating temperature.
SHRTFT B1S1 = Short-Term Fuel Trim for B1S1
O2SB1S1 = Sensor voltage sine wave feedback
Before: Vehicle at operating temps
After:
After: Cruising at 45mph
After: Accelerating hard - pedal to the floor
I have been sent wiring diagrams for testing but i can figure out which connections or wires to test or where they're located. Please help!
Thank you in advance!
I've searched quite a bit for similar posts to my issue, but I cant seem to find anything that helps explain what I'm experiencing. I'm hoping someone can point me in the right direction or has had a similar issue they were able to fix.
The P0135 error is intermittent and can trigger right upon turnover after a cold start, following a hot start, randomly while driving, and often times will remain off for 2-3 starts and many miles of driving. It's HOT and humid in Lincoln, Nebraska right now (95-103 every day with +80% humidity).
Background: 1996 Lexus LX450 - stock other than deleted cats.
- Current Error: P0135 (o2 Sensor Heater Circuit Bank 1 Sensor 1) -- this error was present before replacing the sensor and after.
- Replaced upstream sensor with this Bosch sensor Advance Auto Parts - Down for Maintenance
- The catalytic converters have been removed and a straight pipe was welded in between the upstream and downstream o2 sensors.
- Prior to replacing the original upstream o2 sensor, I was getting P0135 AND P0133 error codes from B1S1 (bank 1 sensor 1). After replacing the upstream sensor, the P0133 error has gone away (Error P0133 = o2 Sensor Circuit Slow Response Bank 1 Sensor 1).
- No errors are being reported from the downstream sensor (prior to removing the cats, I was receiving errors from the downstream sensor as well)
- I have disconnected and dielectric greased LITERALLY every single molex connection under the hood and under the chassis (even to the transmission and everything else).
Installation:
To wire in the new sensor, I disconnected the upstream sensor from the grey factory molex plug and then cut the wires right at the end of the original sensor so I had an OEM pigtail. I then took the new sensor and wired it to the OEM pigtail so I could reuse the OEM molex connector. The new sensor came with an interesting rewire connector assembly which creates a waterproof seal between the connections of the OEM wiring and the new sensor wiring.
YES, I triple-checked to make sure I rewired the new sensor correctly, and YES I checked the heater circuit for continuity/ohms from the OEM molex plug connections through the rewiring assembly to make sure I wired it correctly.
I installed the new sensor into a new hole I drilled into the exhaust because the old sensor was completely rusted in place (i sealed the small air-gaps around the flange for the new sensor placement so there wouldn't be any exhaust leaks). I filled the OEM molex connector with dielectric grease before reconnecting it and zip-tied the excess wiring/connector assembly from the new sensor to the frame.
I'm not sure if these screenshots help at all, but here are the before and after numbers coming from my o2 circuit while driving around at operating temperature.
SHRTFT B1S1 = Short-Term Fuel Trim for B1S1
O2SB1S1 = Sensor voltage sine wave feedback
Before: Vehicle at operating temps
After:
After: Cruising at 45mph
After: Accelerating hard - pedal to the floor
I have been sent wiring diagrams for testing but i can figure out which connections or wires to test or where they're located. Please help!
Thank you in advance!
