P1117 - can't clear code - O2 Sensor replacements
 

98 with 175k kms. All original. No performance mods etc.

I have a durametric so can see codes. I have done my research on here and have O2 sensors on order.

My question: has anyone ever had this issue? And did replacing O2 sensors fix it?

My symptoms:
-CEL: duh. comes on and throws a raft of codes. It's infrequent however. Codes were as follows. NOTE: I can clear the P1117. It's persistent. I can clear the other codes without issue.

P1117 -Heating power 02S behind cat c bank 1

P1319 - Misfire emissions-relevant

P1313 - Cylinder 1 misfire emissions-relevant

P1314 - Cylinder 2 misfire emissions-relevant

P1316 - Cylinder 4 misfire emissions-relevant

P1317 - Cylinder 5 misfire emissions-relevant

P0410 - Secondary air injection system Cylinder (1-3) Signal implausible

P1411- Secondary air injection system Cylinder (4-6) Signal implausible

P1128 - Oxygen sensing range 2 Cylinder (1-3)

P1130 - Oxygen sensing range 2 Cylinder (4-6)

-Performance: minor sluggishness in performance until above 3000rpm. Then is comes totally alive (almost feels like turbo lag!).

-Performance: infrequently I get a major bogging at higher revs. Feels like a sudden loss of power and like fuel is getting cut. Lift off the throttle and the car idles fine. Lasts for maybe 5 seconds. Then fixes itself. Sometimes CEL comes on. Most times not.

-smells like it's running rich at idle.

What I've replaced so far: MAF (made a big difference), all coils and all plugs, fuel pump.

What I've looked at: tried to find a vacuum leak as research leads me to believe this is the culprit for these kinds of codes. Could not find one easily. Decided to tackle O2 sensors 1st after persistent code started occurring.

I'll post back here once I've done the mods to let others know what happens when I swap the sensors.

The P1117 code is for the heating element in the O2sensor.
That heating element is triggered by the ECU as soon as you turn the key on.
The ECU is seeing that the circuit is not complete so it triggers the code.
Probably triggers it just by turning the key to the on position.
So you will not be able to clear that code and keep it cleared tell you fix the issue.

Since the P0410 - P1411 codes are SAI related I would fix the SAI issues before replacing O2 sensors other then the one with the P1117 code.

This is why:
The SAI system is upstream of the O2 sensors so any issues with the SAI "may" have an affect on O2 sensor readings. But the SAI issue will not affect the heating circuit of an O2 sensor because it is an electrical circuit powered from the ECU.

If you replace the O2 sensors before fixing the SAI you could still get bad O2 sensor codes.

Hope this makes sense;)

Thanks for the nice explanation Blue62!

Agree! Thanks for posting the explanation.

Could not find vacuum leak and the SAI pump/fan turns on and off. So I was thinking it's something else.

But appreciate the response and will looks more closely at the SAI system as a whole. Lots of good info on here to research.

Thank you NewArt.;)
Just trying to help the community where I can.

The more you understand a system, circuit, sensor.
And how they relate to other systems, circuits, and sensors, the easier issues with them are to resolve.
That's what I tell myself anyway.:D

I do wonder many times when I try to explain something via this venue.
Does it make sense to another person that reads it? Has it helped?
Could I have explained it another (better) way ?

I think with 175k miles on your car that the plastic hoses, connectors, one way valves and vacuum canister on the SAI system are in need of replacement.

I watched the video you posted the link to in your other post.
He shows the layout and parts involved pretty well.
The SAI system is fairly basic you would just be replacing a few parts.
I would think you could replace everything but the pump for around $200.00
$250.00 ??
I would think you could find vacuum hose and tee or y type connectors at an auto parts store or hardware store that would work.

If your not afraid to turn a wrench I thing you can fix the SAI issue with a little time and a bit of cash.

Let us know how you go.
I am always interested in out comes of those I try to help;)

Thanks again. Yup, the SAI seems an easy enough job. I'll add it to the list!

Might take a while to get to it. But I will post up results and findings. I too like seeing how issues got resolved on here. Helps folks in the future.

I've got a couple of O2 sensors ordered already. So I'll swap the one that throwing the code seeing as it needs doing.

Zzorro

You said the Air pump works so I am going to assume you triggered it with your Durametic to check it.

So you need to make sure the air pump kicks on when you first start the car from a cold start. Confirm that it kicks on from cold start before going further.

This is why.
One of the things the DME/ECU looks at on cold start is coolant temp.
If the coolant sensor shows close to ambient temp. (cold engine). it triggers the SAI air pump.
If by chance your coolant temp sensor does not show close to ambient temp. at cold start.
Then the DME/ECU is going to react as if the engine is already warm so it will not trigger the Air pump. Thus possibly triggering a SAI code.

So a faulty coolant temp sensor that still operates but not properly can trigger other codes without triggering a fault code for a faulty coolant sensor.

Damn
I hope that makes sense:D

You may as well change out all the O2sensors you have replacements for at once.
As after rereading your first post I see you have codes for adaption range issues on both banks.
Those codes could be caused by the SAI issue.
Or the O2 sensors could be causing the SAI issue.
But with 175k miles if the O2sensors are original then replacing them first may be more prudent.
Easiest things first.

Thanks Blue62

One clarification, I have 175k kms or 108k miles. But same difference. The car is up there in age and miles and stuff needs replacement.

To answer your specific questions:
1: yes, will swap O2 sensors. Explanation of my rationale below.
2: yes, I can turn on SAI pump with durametric.
3: yes, SAI turns on on cold start, have confirmed it.

I am suspecting O2 sensors over the SAI because:
-all the other codes thrown
-smells to me like it's running rich on idle. Totally subjective opinion
-engine bogging issue (and subsequent CEL) happens after the car is warmed up and in higher revs.
-you pointed out that one of my O2 sensor heater elements is probably pooched anyways.

For the benefit of those joining in the conversation:

Based on my research on here and other places, the primary culprits are 1) MAF, 2) vacuum system (which the SAI plays a part in) and 3) O2 sensors.

1) I already replaced the MAF (and that made a huge difference). 2) The SAI functions and I could not locate a vacuum leak easily (idle drops when oil cap is pulled off and starter fluid sprayed near the hoses and parts did not blip idle at all). 3) Next on the list is the O2 sensors.

Should note also that I replaced my AOS already and that did get rid of blueish smoke on startup.

Your p1128 and p1130 codes for oxygen sensing range 2 are interesting in that one code is saying your at the lean limit on one bank and at the rich limit on the opposite bank. So replacing the O2 sensors may very well take care of those two codes.

Also if you have faulty O2 sensors the SAI can fail it's self test because the ECU uses O2 sensor reading to confirm air injection (lean condition) in the exhaust when it triggers the air pump for the self test.

Watching with interest;)

While waiting for my O2 sensors, I ran the durametric this morning.

1: confirmed SAI pump turned on again right away.

2: O2 sensors ahead and behind cat seems to be running in spec
http://986forum.com/forums/uploads02...1598723545.jpg
http://986forum.com/forums/uploads02...1598723577.jpg

3: picked up some codes. P1117 and P1040 before I started the car. I was able to clear them both this time. And they have not come back.

I'll swap all four O2 sensors and see what happens. For the effort to tackle the SAI system, I'll probably take a look at it too.

More reading and I found a few spots where the post cat O2 sensor failure has lead to bogging and hesitation / loss of power at high revs. This is one of my performance symptoms and happens only occasionally for shot bought (a few seconds).

Anyways. Fun and games.

after you get your O2 sensors changed out.
Here is a way to test the SAI system to see if the air from the air pump is getting to the cat as it should.
With the Durametric hooked up and watching both pre cat O2 sensors.
Get the car warmed up and into closed loop.
Have the engine at idle.
Trigger the SAI pump so it is pumping air.
Your pre cat O2 sensors should go low in voltage.
Around .250 Mv or less.
Not exactly sure of the voltage but should go low and stay low as long as the air pump is running.
Here is why:
When you pump air into the exhaust the O2 sensors should see it and show a lean condition. (excess air). lean is low O2 sensor voltage. Rich is high O2 sensor voltage.

Another way to see if the air from the pump is getting into the exhaust.

With engine off run the air pump and see if you have air escaping at the tail pipe.
Don't know how well that works with pre and post cats.

I prefer to see O2 sensor voltage drop because that is what the DME/ECU is looking at when doing the SAI self test.

If neither of these tests work then air from your SAI pump is not getting into the exhaust.

So assuming you have no vacuum leaks.
Then the air pressure hose from the pump to the engine has a leak.
You have a bad combination valve (the one actuated by vacuum) or bad change over valve. (the electric triggered one) Or plugged air passages in the heads.

Hope this helps

Makes good sense. Thanks Blue62! Can run these tests before O2 sensors get swapped. When I get a chance I'll post up with results.

2 of 4 O2 sensors delivered. Waiting for the other 2 to arrive.

CEL came on again, so I thought I would read the codes and post up.

P1128 - Oxygen sensing range 2 Cylinder (1-3)

P1130 - Oxygen sensing range 2 Cylinder (4-6)

P1117 - Heating power 02S behind cat c. bank 1

P0140 - O2 sensor behind cat conv. Cylinder (4-6)

It will be interesting to see what happens once you change out the O2 sensors.
Looks like your not getting the SAI codes anymore?

Blue62, I ran the tests. When the SAI runs, the voltage drops way low. So the SAI is basically working properly (according to that test anyways). I could not feel air from the tailpipe after activating the SAI with the engine off.

What is interesting is the behavior of the O2 sensors as the car is warming up. The post cat voltages hover around 1v. But go up and down up to .99 and 1.06 (blue and red). The pre-cat O2 sensors bounce up and down but not that crisply. Seem like they are getting a bit "lazy" (green and yellow).

Anyways, second set of O2 sensors should be here this week. Then I'll swap them all and see what happens.http://986forum.com/forums/uploads02...1599514531.jpg

That test of the SAI that I described to you is exactly what the ECU does to test the SAI. The test I described is just a way to force it manually;)
So if it drove your pre cat O2 sensor voltages low then it seems your SAI is working properly.

If your not fully warmed up and watching your O2 sensors you could still be on a cold start fuel map so it may be a little rich. Also the Cats may not be fully lit off and hot enough to function optimally. So post cat O2 sensor readings could show rich (high voltage).

What RPM are you at when you take the screen shots of the O2 sensor graphs??
I am guessing idle.
Try getting fully warmed up. Then bringing the RPM up to 2000-2500 RPM and look at the O2 sensor reading and see if there is much difference.

Your O2 sensor graphs don't look quite right to me. And it's really hard to tell much by just a screen shot. but your changing them out anyway so no big deal:D

How is it running??

Correct: screen shot is from idle, just after start-up and after SAI pump stopped running. Car got to warm temperature while idling and the readings were much the same. Car seems to run just fine.

Once you get the O2 sensors changed out graph the readings again.
But take it for a drive first so your sure the Cats are hot.
Graph them with the RPM's held around 2000-2500.
Your post cat graph lines should look much like the screen shots you posted.
but in the .450v range.

The 1.00v-1.06v in your screen shots seems out of range to me.
But they were tested at idle just after cold start.
But your changing them out so not important at this point.