Recurring bank 1 O2 sensor code

[j91z28d1]

So I ran live scan on O2 sensor. It's reading just fine

so the idea is exhaust leaks before the o2 suck air in, and even thou the o2 shows switching, that's the ecm believing what it's told, even thou what it's being told is off because of the extra o2 coming from the leak. the ecm doesn't know that and will do everything it can to make the a/f swing believing the o2 signal, it doesn't really know anything is wrong till you get so far out that it hits a hard limit, something like plus or minus 20% adjustments before it thinks something is wrong and throws a code. that condition might not hit at idle, but it could under a different driving condition.

or the leak isn't big enough to really hurt anything, you have a different problem but won't really know till trouble shooting leads you there. along the way, you fixed the leak to rule it out.

 

[ukrkoz]

Yep. That's the bright idea. And, considering that it takes time to show, it's "leak isn't big enough to really hurt anything,"

 

[ukrkoz]

OK, so I finally got to replacing that gasket today. DTC was gone for lioke a month, then popped up 2 days in a row, then vanished again for over a week. I have day off, so I finally did it.
No, no need to remove manifold. Simply undo plug connectors, remove rear plug wire completely, as it gets in the way, and undo all the bolts.
Fortunately, whoever worked on my engine, didn't really torque them too much, so I had no issue undoing bolts.
With the last bolt undone, manifold simply slips out and a bit down.
They apparently reused the old gasket. Picture tells it all. Now I need to redo the pass side one, knowing what I know. Likely, same condition.
Biggest hassle was to slide gasket back in place through about half inch gap and secure it on bolts. I used 2nd bolt from the front first and needle nose pliers to direct gasket onto the #3 bolt.
Manifold tilts down some, so I had to reach and grab the far end of it to tilt it up, for the last 2 bolts to go in place.
Just start bolts in threads and do NOT tighten them, until you have the one by the firewall in place.
Then simply tighten and torque.
You have to, pretty much, lay down on the engine, to reach those rear bolts.

 

[ukrkoz]

BTW, the original DTC code.... It's not actually bad sensor code. It's sensor circuit code. Apparently, there's bad connection somewhere in that circuit, that's why it pops on and off.

 

[ukrkoz]

Just did the passenger side gasket.
What a ***** to do.
The rear bolt you can use only a ratcheting wrench, as there is some sort of AC tray next to it and 2 AC lines. Access is very limited - and very far deep there.
Plus, jerks that worked on that engine left me with 3 13mm bolts and 3 10mm bolts.
But it's done. Gasket was not in any better shape, than the left side one. Clearly signs of exhaust leak.
As unpleasant surprise, oil dipstick tube fell off its bracket. Looks like 3 tack welds got tired.
Right now, I have it taped in place. Tomorrow, will pull some kevlar tape, saturate in resin and wrap it in place together. Will hold better than welds. Just tired, it was quite a work out, half of it laying on the engine to reach back there.

 

[Geotrash]

Just did the passenger side gasket.
What a ***** to do.
The rear bolt you can use only a ratcheting wrench, as there is some sort of AC tray next to it and 2 AC lines. Access is very limited - and very far deep there.
Plus, jerks that worked on that engine left me with 3 13mm bolts and 3 10mm bolts.
But it's done. Gasket was not in any better shape, than the left side one. Clearly signs of exhaust leak.
As unpleasant surprise, oil dipstick tube fell off its bracket. Looks like 3 tack welds got tired.
Right now, I have it taped in place. Tomorrow, will pull some kevlar tape, saturate in resin and wrap it in place together. Will hold better than welds. Just tired, it was quite a work out, half of it laying on the engine to reach back there.

It’s MUCH easier to remove the front tires and fender liner, and go in from the side. Terrific access that way. Sorry I hadn’t seen your previous message sooner or I would have mentioned it. But, you got it done. Nice work.

 

[Dustin Jackson]

@ukrkoz I recommend taking the old dipstick to the parts store to compare, apparently there are a few variations and I had to go back and get the right one

 

[ukrkoz]

@ukrkoz I recommend taking the old dipstick to the parts store to compare, apparently there are a few variations and I had to go back and get the right one

Why? Dipstick is in place, it just parted with the supporting bracket. I mean - DS tube parted. It's all secured back in place 20 min ago. Any reason to replace DS?

 

[Dustin Jackson]

@ukrkoz Yes I was meaning the dip stick tube also. I guess you don’t need to replace it