MotorOilInTheVeins
New Member
Ok guys this one is going to stump you. (hopefully not)..
2006 Sequoia Limited. 189,000 miles.
Backstory: Driving on interstate around 75 mph, no signs or lights and then all of a sudden the aftermarket radio turned off. Seconds later the dash lit up like a Christmas tree. Pulled off the interstate and noticed it losing power, chugging, backfiring and sputtering..
Ok, first thought is that it was a dead battery but it turned out to be the alternator was dead. It was dead and then killed the battery too. Replaced that and the battery since it was 5 years old anyway, it was only inevitable.
A few days later the check engine light came on. My basic code reader said 420/430 codes, "catalyst below limits".
I researched and found that a catalytic can go bad especially with high mileage. Before I went crazy buying expensive parts, I decided to buy an expensive tool. Bought a OBD scanner with bi-di information feed. Been nice to see whats going on in real time. Both front O2 sensors were reading high at 3.9 volts when everything I read says that standard is 3.3v.
- Replaced two front O2 sensors.
Still pops a code at 20 miles after reset.
Exhaust stinks, but not terribly just not like a clean exhaust would be normally.
- Yep, replaced the Cats..
Reset the ECM and bang 20 miles... Code 420 only this time which indicates left bank has issues.
Checked and compared the running voltage at 1500 rpm and scanner shows erratic rear left side O2 sensor.
- Replaced that left rear sensor.
Still popping a 420 code only BUT the O2 sensors are at least stable and equal voltages now.
I have checked for obvious air intake leaks, no exhaust leaks, both sides sealed up good on exhaust.
Pulled the spark plugs looking for signs or clues and nothing there.
This one has got me baffled and I am a bit nervous a dealer isn't going to use lubrication when they screw me.
Any wisdom is greatly appreciated.
2006 Sequoia Limited. 189,000 miles.
Backstory: Driving on interstate around 75 mph, no signs or lights and then all of a sudden the aftermarket radio turned off. Seconds later the dash lit up like a Christmas tree. Pulled off the interstate and noticed it losing power, chugging, backfiring and sputtering..
Ok, first thought is that it was a dead battery but it turned out to be the alternator was dead. It was dead and then killed the battery too. Replaced that and the battery since it was 5 years old anyway, it was only inevitable.
A few days later the check engine light came on. My basic code reader said 420/430 codes, "catalyst below limits".
I researched and found that a catalytic can go bad especially with high mileage. Before I went crazy buying expensive parts, I decided to buy an expensive tool. Bought a OBD scanner with bi-di information feed. Been nice to see whats going on in real time. Both front O2 sensors were reading high at 3.9 volts when everything I read says that standard is 3.3v.
- Replaced two front O2 sensors.
Still pops a code at 20 miles after reset.
Exhaust stinks, but not terribly just not like a clean exhaust would be normally.
- Yep, replaced the Cats..
Reset the ECM and bang 20 miles... Code 420 only this time which indicates left bank has issues.
Checked and compared the running voltage at 1500 rpm and scanner shows erratic rear left side O2 sensor.
- Replaced that left rear sensor.
Still popping a 420 code only BUT the O2 sensors are at least stable and equal voltages now.
I have checked for obvious air intake leaks, no exhaust leaks, both sides sealed up good on exhaust.
Pulled the spark plugs looking for signs or clues and nothing there.
This one has got me baffled and I am a bit nervous a dealer isn't going to use lubrication when they screw me.
Any wisdom is greatly appreciated.
