V70 2.4T (P2) ECM-262A (P2097) -upper O2 sensor? -NOPE! Vacuum, Evap & Intake leaks! Topic is solved

Jonboy74 · Post by **Jonboy74** » 12 May 2020, 11:43

Hi guys & gals,

Just want to make sure I’m on the right track here.... I’m thinking I need to replace the upper O2 sensor?

Here’s the history:

Replaced a bad coil (got a specific coil code) a while back, thought everything was grand, and then a short while later started running rough again and CEL came on. Cheap code reader pulled a P2097 “Post Catalyst Fuel Trim System Too Rich Bank 1”

Connected VIDA and got ECM-262A, along with these details:

When I go into Vehicle Communication, click on ECM, and then under Parameters, I clicked on all 4 of the Oxygen Sensor parameters, these are the readings I get in real time with the car idling (640 RPM) and engine up to temperature (94.5 deg C):

Oxygen Rear Sensor, bank 1 :: 0.22 V
Oxygen Rear Sensor, bank 2 :: -0.2 V
Oxygen Front Sensor, bank 1 :: 1.33-1.38
Oxygen Front Sensor, bank 2 :: null

If I rev the engine up to ~3,000 RPM, I get these readings:

Oxygen Rear Sensor, bank 1 :: 0.28 V
Oxygen Rear Sensor, bank 2 :: -0.2 V
Oxygen Front Sensor, bank 1 :: 1.01
Oxygen Front Sensor, bank 2 :: null

When I let off the gas and it drops back down, I get these readings (at 880 RPM)

Oxygen Rear Sensor, bank 1 :: 0.21 V
Oxygen Rear Sensor, bank 2 :: -0.2 V
Oxygen Front Sensor, bank 1 :: 5 (yes, five)
Oxygen Front Sensor, bank 2 :: null

I don’t appear to have any intake or exhaust leaks. The engine will typically die when I start it unless I step on the gas a bit during starting. I don’t have ANY trouble with driving on the highway or acceleration (plenty of power, which I know I would not have if the turbo intake were leaking).

So....upper O2 sensor?

Thanks!

Jonboy

PS: For anyone else who reads this and doesn’t have VIDA....this is what VIDA says about ECM-262A:

ECM-262A (P2097) Long-term fuel trim. Upper limit

Diagnostic trouble code (DTC) information

Condition
The control module receives information from the heated oxygen sensor (HO2S) about the fuel / air mixture when idling at both the lower and upper part-load range. If the fuel / air mixture deviates from λ=1, the short-term fuel trim will compensate for this by adjusting the injection time so that λ=1 is achieved. When the short-term fuel trim makes an adjustment, the integrator median must be adjusted by the long-term trim. Diagnostic trouble code (DTC) ECM-262A will be stored when the long-term trim must be adjusted almost to maximum in the idle range.

Substitute value
none

Possible source
Upper limit:
intake air leakage
exhaust system air leakage
defective heated oxygen sensor (HO2S)
Lower limit:
intake air leakage
high fuel pressure
leaking injectors
defective mass air flow (MAF) sensor
contaminated engine oil
oil level too high
defective heated oxygen sensor (HO2S)

Post by **- Pete -** » 12 May 2020, 11:50

What kind of voltages do you get under load (ie: driving w/boost) w/ViDA/DiCE hooked up?
Upstream is definitely reporting high values.

Jonboy74 · Post by **Jonboy74** » 12 May 2020, 12:19

- Pete - wrote: ↑12 May 2020, 11:50 What kind of voltages do you get under load (ie: driving w/boost) w/ViDA/DiCE hooked up?
Upstream is definitely reporting high values.

Hi Pete - I’m not sure honestly. Is there a way to record that in VIDA? If so, I’m not sure how....

Thanks,

Jonboy

Post by **abscate** » 12 May 2020, 14:08

don’t appear to have any intake or exhaust leaks. The engine will typically die when I start it unless I step on the gas a bit during starting. I don’t have ANY trouble with driving on the highway or acceleration (plenty of power, which I know I would not have if the turbo intake were leaking).

That’s pointing to vacuum or intake leaks. You should start, to a fast idle, and one minute come down to 850 rpm smooth as silk.

Unmetered air will mess up your fuel trims, cat readings, etc.

Do the deep dive visual inspection, removing everything, smoke test if nothing found, and look at those fuel trims at idle and at 2500 rpm after warmup

Jonboy74 · Post by **Jonboy74** » 12 May 2020, 21:33

abscate wrote: ↑12 May 2020, 14:08 Do the deep dive visual inspection, removing everything, smoke test if nothing found, and look at those fuel trims at idle and at 2500 rpm after warmup

Ok, so I have to confess, I have never traced or even attempted to trace a vacuum leak before. It’s always been something the shop has done for me....and when they come back with “you had a vacuum leak.....” I kinda have shrugged and said ok....

Is there a guide (or better yet, a video) on here anywhere that will point me in the right direction?

Thanks,

Jonboy

Post by **- Pete -** » 12 May 2020, 22:30

To get you started, don’t obligate yourself to do the job twice. Have new vac hose ready to install. Get THIS stuff ahead of time. Most vac hose available is ~2mm wall thickness. The above is 4mm ID & 3mm wall thickness.

Obviously inspect the lines best you can, but replace them all while you’re there. It’s not a huge pain, but you will get dirty & your forearms will probably be scraped up a bit. Definitely not worth having to take stuff apart twice over.

You’ll need to remove the airbox, then remove the turbo inlet hose (this is the one that contains your MAF). There is a hose clamp where the inlet hose meets the turbo; on it is a 7mm worm drive screw you’ll need to back out. I use a swivel head 1/4” ratchet for obscure ones like this.

Past that, it’s just a matter of tracing your vac lines. Use a pliers on each barb to twist the rubber hose just enough to break its seal. Then they should all just pull off. The original hoses will be marked with colored tape. When I replace hoses I like to use colored electrical tape to coordinate with what came from the factory.

Also, if you’ve never replaced it before, it’s likely a good time to also install a new TCV/BCS. Those stand for Turbo Control Valve/Boost Control Solenoid, they are the same thing but both terms are used interchangeably. I believe P2’s book at 30-40k change intervals for these.
Yours should use part number Pierburg 30670448.

Edit: I will be doing new vac lines on one of my P2’s soon. I’ll take photos & write something up. Definitely will not be in video format

Also, I took a screenshot in ViDA earlier showing how to log your parameters on a graph while driving. Need to find where I saved it.

Jonboy74 · Post by **Jonboy74** » 13 May 2020, 00:27

Thanks Pete

Something was bugging me about this and then I realized I had a similar situation a couple years ago.

viewtopic.php?f=9&t=85520&p=473930&hilit=P2097#p473169

My indie shop ended up replacing that valve @ 237k miles

I’m at 263k now.

I’ll take a look and see what I can figure out. I would not at all be surprised if I have another vacuum leak or my Turbo intake isn’t as tight as it should be.

Thanks!

Jonboy

Jonboy74 · Post by **Jonboy74** » 10 Sep 2020, 23:44

Hi all,

To close the loop on this thread, I ended up just going in and replacing all of the vacuum lines going to the Turbo, cleared the CEL, and the code never came back...and it passed NC Emissions Inspection. Cost all of $35 plus my time to do the job.

The vacuum lines appeared to be all original, and the stuff Pete suggested worked a treat.

I don't know why I avoided this for so long - nowhere near as intimidating as I thought it would be....

Now the question is whether I should replace the PCV Breather Box, because I'm betting it has never been done before....

Goodnight Elizabeth!

Jonboy

Post by **abscate** » 13 Sep 2020, 00:06

263k miles is a lot on an original Pcv system on a Volvo. Read up on the banjo bolt and plan on an afternoon to do that.

Goodnight Jonboy!

Elizabeth

Jonboy74 · Post by **Jonboy74** » 23 Sep 2021, 20:44

- Pete - wrote: ↑12 May 2020, 22:30 To get you started, don’t obligate yourself to do the job twice. Have new vac hose ready to install. Get THIS stuff ahead of time. Most vac hose available is ~2mm wall thickness. The above is 4mm ID & 3mm wall thickness.

Hi Pete (or anyone else who may be reading this and have the answer) - I know this is from more than a year ago, but when I did this, I also replaaced other vacuum lines that were a larger inside and outside diameter than what you spec'd above. What you spec'd worked perfectly, however the other hose looked more like fuel line. I replaced it with the closest match I could get from the auto parts store, but it was really tight - I suspect that the correct tubing is metric and what I got was 5/16" or something like that.

Anyway - some of it has split, and causing me grief again. Any idea whata the correct tubing size is for the larger diaameter tubing?

Thanks!

Jonboy