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.

Actually I believe I was wrong about the post cat O2 sensor voltage that I posted previously.

If the cat is working properly then it is using up all the oxygen in the catalytic process.
Therefore the post O2sensor should show a relatively flat high voltage reading.
This is fully warmed up and RPM held steady around 2000 RPM.

Started the O2 sensor swap.

They are seized in there pretty good. I'm soaking them in PB Blaster overnight. I will tackle again tomorrow.

Relatively easy so far though. All 4 connections are easy enough to reach and the red "plunger" on the connections came loose with a small screw driver a little leverage.

I always use a 50-50 mix of Acetone and transmission fluid.
Shake the hell out of it, apply several times over 24 hours.
Has always worked better then anything purchased off the shelf.

Are you talking about automatic transmission fluid?

Yes automatic transmission fluid.

3 of 4 removed. Some good removal tips. I needed to cut the wires because the slotted socket was def going to round out the O2 sensor. Box end wrench, a little heat and a few whacks and 3 of them came loose. The other one is being an *-hole.
http://986forum.com/forums/uploads02...1600042012.jpg
http://986forum.com/forums/uploads02...1600042058.jpg

I'll try again on the last one tomorrow.

Slow and steady you'll get it.

I got it.

http://986forum.com/forums/uploads02...1600128416.jpg

Now to install the new sensors. I opted to buy Bosch 15738 units. These are the OEM sensors with a DIY connection to use the original connectors. The Bosch connection system is pretty slick so I think it will work.

http://986forum.com/forums/uploads02...1600129069.jpg

So main question: does it matter how long the wire leads are? The existing O2 sensor leads are about 6" long. Seems to me that a little extra wire wouldn't do any real harm right? Can just coil up the extra?

I don't see what it could hurt as long as you don't kink it.

All sensors swapped. Plugged in the durametric and ran car for 5 mins to confirm they were all sending signals. They were. Then shut down for the night. Will run thru paces tomorrow and post up results.

Wondering if there is a run-in period for O2 sensors. Assume I got to get them good and hot etc. Read someone say that it take some time for the ECU to adjust the fuel mapping etc for new sensors. One post talked about disconnecting and reconnecting the battery or something. Didnt sound right to me.

Anyways. Thanks all for the advice and Blue62 for guidance. Look forward to posting up results.

There is no run in period needed for the O2sensors;)
I would take it for a good cruise, 20-30 minutes should be enough time for the DME/ECU to readjust fueling to the new sensors. No need to disconnect and reconnect the battery.
Make sure you clear all your codes first.
Looking forward to your follow up post. Expecting good results;)

Success I think. Ran it for 40 mins in town this evening with durametric plugged in to monitor. No CEL or codes. Seems like the O2 sensors are doing their thing.

The car feels different somehow. The noticeable feeling of increased power at 3500 rpm onwards has smoothed out. So I think that means that I should have a bit more at the lower end? Anyways. Need to drive it a bit more to see what else is different. I think it's going to take a while to get the ECU to figure itself out as well, so more fun KMs ahead!

Here is a snapshot of the graph after the drive (warm engine) at idle.

http://986forum.com/forums/uploads02...1600229534.jpg

Good to hear things are working out.
I would be interested to know if things stay good a few hundred miles on.

Most codes if they are not harmful to the cats take two back to back drive cycles to set the CEL.
But codes can be stored in the pending code area of memory on just one instance.
So I would keep an eye on the pending codes as well.

Got another 100kms from driving yesterday. 50 kms to work and back. On the way back home I didn't get a CEL but I did get a recurrence of an issue if have been trying to chase down.

The car will "stumble" or loose all power at higher revs. It will just bog right down under load. It feels like it's not getting fuel, but when I take my foot off the gas it returns to idle just fine and does not stall.

To remedy this, I shut off the car and restart it. After the restart it works fine again like nothin happened. During previous occurrences it would sort of stumble along for a min and then return to normal, be like nothing happened. But I just restart now. This happens very infrequently. Maybe once every 800kms to 1000kms? Sometimes I get a CEL and sometimes I don't.

To address this issue specifically I have replaced the fuel pump. Then I did the coils and plugs and all O2 sensors. Plus earlier I replaced MAF. Apart from the fuel pump, the latter items are all related to clearing codes and needed to be done anyways. (So I'm not throwing parts at the car for this issue specifically). But thought that getting some of these parts would take care of this issue.

Anyways, because the issue is so intermittent, I'm asking if checking fuel pressure or injectors will even help? Could this be something to do with the ECU itself maybe?

Difficult issue to diagnose remotely but your sense that it may not be getting enough fuel may be a starting point.

Good diagnostic procedure says start with the simplest things first so:

With the age and mileage on your car when was the last time your fuel filter was changed?

I am going to assume your air filter is clean;)

I would do a fuel pressure test just so it is not an unknown. Not difficult to do.

How is your throttle set up?
Is it mechanical? Or throttle by wire like my 2000S?
I ask because I am wondering about possible throttle position sensor signal issues.

Does the issue happen at the same RPM range every time?

The fact that you can shut it down - restart it and everything is fine sounds like an electrical gremlin.
Which would make one think ECU issues, but if it is an electrical issue it could be in any number of places.

If you know how to data log with the Durametric ( I have never tried it) and you can force the issue to occur.
You may be able to spot something in the data log that could give you some clues as to what's going on when it looses power.

Thanks Blue62 for the feedback and willingness to help out. To answer your questions:
1: fuel filter was changed with the fuel pump (approx 2000 kms ago) Sorry, forgot to mention

2: the air filter is a k&n unit that came with the car. I cleaned it and made sure it's not over-oiled. I suspect the PO over-oiled it, which may be why the MAF went bad. Anyways, I plan on swapping that out for an OEM paper filter one of these days

3: 10-4 on fuel pressure test. Have looked up the procedure and will get to it eventually.

4: it's throttle by wire. Mine is a 98. There is a sensor for throttle angle. I should note that when I did the MAF I took the air intake piping apart and cleaned it all based on advice found here. There was def some oil build-up in and around the throttle body. AOS and maybe air filter over-oiled etc. Anyways. That got cleaned up.

5: yes, around the same RPM range is when is starts bogging. Above 3000 I would guess. Car revs up great, then on the way up starts stumbling and sputtering and complete loss of power. I pass the gas and it just bogs down and feels like it's gonna stall, but doesn't. Maybe it's ignition related? Or fuel supply problem.

6: I'll have to look up durametric logging. I know it's on there and easy enough to figure out. The issue for me is logging while the issue occurs. It happens so infrequently that it's always a surprise :-).

Speaking of electrical gremlins: my CLU is messed up. I got all kinds of them (windows don't roll down, but do the drop, FOB and alarm don't work etc.). I will get to fixing it eventually. But the car has always started and run etc. Considering the frequency of occurrence maybe the engine and CLU do a self diagnosis every so many KMs and because the cLU is messed up it forces the car to stop providing fuel or something (thinking the car is stolen?). Sounds far fetched to me, but maybe?

I wonder if a solenoid on one bank or the other is not kicking the Variocam system in when your lose of power issues occurs???? Just a thought.

Researching now. I'll hook up durametric and snoop around a bit. See if I get consist actuation and look at the deviations etc. But it does look like others have reported similar symptoms with variocam.

Finally got around to hooking up the durametric.
I am able to activate both banks variocam solenoids and I get a def change in engine behavior when I do at idle. So theoretically these actuators are working properly.

My stumbling issue could be related to inconsistent operation of one or both of these actuators maybe? Will keep an eye on it.

On another note, my crank deviation position reads 0 degrees. Not sure if that's normal or not. Assumed I would see some deviation considering the age of the car.

I assume you mean camshaft deviation.
0 camshaft deviation does sound unusual.
Take the car for a 20-30 minute drive then take the reading.
What ever reading you get it should stay steady no matter the RPM.