Upstream oxy sensor early life failure?!?
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MBWorld Fanatic!
Joined: Jun 2010
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From: Emmett, ID, USA
2007 GL450
Upstream oxy sensor early life failure?!?
I changed the bank 1 sensor 1 about 6k miles ago. At 4K miles, saw a P0133 error: Slow response. Now I got P0135, heater malfunction.
Here's the question, fam: What are the odds this is something besides the core of the sensor itself? Like the plug connector, some jive on the ECU?
Here's the question, fam: What are the odds this is something besides the core of the sensor itself? Like the plug connector, some jive on the ECU?
MBWorld Fanatic!
Joined: Dec 2004
Posts: 4,268
Likes: 253
I changed the bank 1 sensor 1 about 6k miles ago. At 4K miles, saw a P0133 error: Slow response. Now I got P0135, heater malfunction.
Here's the question, fam: What are the odds this is something besides the core of the sensor itself? Like the plug connector, some jive on the ECU?
Here's the question, fam: What are the odds this is something besides the core of the sensor itself? Like the plug connector, some jive on the ECU?
Thread Starter
MBWorld Fanatic!
Joined: Jun 2010
Posts: 2,762
Likes: 630
From: Emmett, ID, USA
2007 GL450
I took a look at pending codes: P0174, P0133, P0153.
153 is the bank 2 upstream slow to respond. The same error, both sides. Coincidence or ECU or MAF sensor (?).
It's along with the 174 error (too lean). I'd had this error before; it didn't recur after cleaning the sensor, but now it's back. Seems to suggest it's the sensor.
I'll swap the sensor (I have a spare on the shelf) and post back.
153 is the bank 2 upstream slow to respond. The same error, both sides. Coincidence or ECU or MAF sensor (?).
It's along with the 174 error (too lean). I'd had this error before; it didn't recur after cleaning the sensor, but now it's back. Seems to suggest it's the sensor.
I'll swap the sensor (I have a spare on the shelf) and post back.
Thread Starter
MBWorld Fanatic!
Joined: Jun 2010
Posts: 2,762
Likes: 630
From: Emmett, ID, USA
2007 GL450
Update: I swapped the sensor and, while I was in there, removed and gave some lovin to the big elbow the sensor sits in. The seal and strength of connection to the throttle body / intake manifold was kinda flimsy and loose. I doubt it was leaking significant air, but it may be that oil leaking down from it (that's where the PCV hose connects) is responsible for the residual oil burn smell after I replaced the cam housing plugs.
If you get in there, I'd take some time to clean it all up and make sure that elbow is seated correctly. It's a disturbingly flimsy attachment, and muscling the air cleaner housing on seems likely to dislodge it. I also lubricated all the rubber parts with silicone grease to make them fit together more easily.
Anyway, bottom line on the MAF sensor change: It's been a few miles and no recurrence of the oxy sensor errors. I'll post back if they recur.
The MAF sensor might be a good place to start if you get funny fuel system errors. It's cheap and easy to replace.
Update 2: So far, so good. None of the oddball errors.
If you get in there, I'd take some time to clean it all up and make sure that elbow is seated correctly. It's a disturbingly flimsy attachment, and muscling the air cleaner housing on seems likely to dislodge it. I also lubricated all the rubber parts with silicone grease to make them fit together more easily.
Anyway, bottom line on the MAF sensor change: It's been a few miles and no recurrence of the oxy sensor errors. I'll post back if they recur.
The MAF sensor might be a good place to start if you get funny fuel system errors. It's cheap and easy to replace.
Update 2: So far, so good. None of the oddball errors.
Last edited by eric_in_sd; Mar 20, 2019 at 05:39 PM.
