A couple things members might know, that I don't.

[liambean]

I bought a 2001 V70 2.4T from Bend Oregon. I live in Las Vegas. I've had a check engine light problem from the get-go, but I'm starting to suspect that the car is just having to learn all over again after having been without power for months.

The car is in beautiful shape for a 20Y/O model. One owner and he or she treated it like a favorite child. Low miles (116,000 or 6,000 mi per year). no dents, minor scratches, and it runs great. Just that damned light.

At first I was getting P0141 code; that stopped. Then I started getting a P0136, same sensor,different problem. Also just before the P0136 tripped I always got a "gas cap loose" warning. It wasn't, and here lately that has also stopped. Now it's just the P0136 code.

Finally, it takes longer and longer (more and more miles) before I get the P0136 DTC.

Also, the sensor looks new; no dirt on it. Still as shiny as if it just came out of the box. I can't make out who made the sensor.

Is it possible the CEM or ECM will finally reprogram itself enough for this to stop on it's own? Like the lose gas cap warning? Again, I suspect that the car sat without battery power for an extended period of time.

Thanks for any and all input.

[br0dy519]

The CEM/ECM didn't reprogram themselves to clear your error. You just had a drive cycle or three where it didn't show a fault. I, with my limited knowledge, believe your car is telling you that you have both an exhaust leak and an EVAP leak.

[RickHaleParker]

Clean connector and inspect harness for shorts and opens.

For both P0136 & P0141.

Possible source
Signal too high:

• short-circuit to supply voltage in the signal cable
  defective heated oxygen sensor (HO2S).

Signal too low:

• short-circuit to ground in the signal cable
  defective heated oxygen sensor (HO2S).

Signal missing:

• contact resistance and oxidation
  open-circuit in power supply from system relay.

Faulty signal:

• defective heated oxygen sensor (HO2S).

[liambean]

I found the problem with the downstream O2 sensor. Seeing as the wiring is stainless steel, and my pulling on the wire was not hard enough to do this, I suspect someone tried to change the sensor (it was easy to unscrew from the converter), and didn't know what they were doing. Yes, I pulled on the wire go get it through the maze of tubes and wiring looms so I could disconnected it. No, I didn't twist it.

Once again prior responders prove they know what they are talking about.

[darrylrobert]

these cars are fairly good at throwing you codes, just wait for the car to start playing up and get no codes ...thats when the fun starts

you have a 2001 same as me, if the car "hard starts" in hot weather check the key ring immobilizer sensor, very common failure and no codes in early stages of failure.

[liambean]

Thanks. I'll keep an eye out. I live in "hot weather central;" Nevada.
My final code fix is "gas cap loose." I have a new cap, so I know that's not it. Replaced the EVAP hoses under the hood and now need to do the same near the right wheel, and back to the canister.

[liambean]

Update: The "J" hose from the EVAP charcoal canister had a crack in it, right at the connection to the canister. I could not see that crack due to the fact that it faced away from the rear of the car. To see it I would have to have stalk eyes like a crab or a snail.

I found it with a smoke generating machine. Once I got the smoke going, and put some light pressure on the EVAP system, the leak was obvious. I then pulled the hose off and sure enough, there was a half inch long crack starting at the open end to 1/4 of the way toward the "U" bend.

I removed the cracked section with diagonals, which made the hose shorter, but it still fits. I used a wire-tie to snug it to the canister. The hose is now pretty short, not that it was that long to begin with. However, it is not rubbing against anything and it's not putting undo strain on anything, including the EVAP purge valve.

Now that I've fixed the leak (no more smoke anywhere) I'd like to know where I can get a new "J" hose. FCP Euro does not carry them.

Thanks in advance.

[RickHaleParker]

I can get a new "J" hose. FCP Euro does not carry them.

Yes you can get a new one for ~$25.00. There are three different part numbers for the 2001 V70. Post the 17 digit VIN number and I'll tell you which one and where to get it?

[liambean]

I can get a new "J" hose. FCP Euro does not carry them.

Yes you can get a new one for ~$25.00. There are three different part numbers for the 2001 V70. Post the 17 digit VIN number and I'll tell you which one and where to get it?

I found one on Amazon, but two of the four reviews were negative stating that the hose lasted less than a year. The others fitment is questionable.
Also, some recommended hose clamps would be much appreciated. This is an ultra low pressure system (under 1/2 an atmosphere), but I want the hose to stay put.
My VIN is YV1SW58D712114301.
Thanks in advance.

[RickHaleParker]

I found one on Amazon, but two of the four reviews were negative stating that the hose lasted less than a year.

Sounds like a ÜRO part. Avoid ÜRO like the plague.

Also, some recommended hose clamps would be much appreciated. This is an ultra low pressure system (under 1/2 an atmosphere), but I want the hose to stay put.

I use Oetiker clamps.

My VIN is YV1SW58D712114301.

Volvo part number 9155990.
FCP euro does not have it.
IPD+ $22.99 .
Volvo Parts Web Store $19.72 .
eEuroparts $24.39 .

Google "Volvo 9155990" you will find other sources ... once again Avoid ÜRO like the plague.

uro- “urine”
/ˈyo͝orō/
combining form
prefix: uro-

relating to urine or the urinary organs.
"urogenital"