ODBII diagnosis

[esl_97_850_T5]

I use the BAFX bluetooth reader

+1 Works great with Torque Pro and volvo850diag, haven't tried 850 OBD-II .

https://www.amazon.com/dp/B005NLQAHS/re ... UTF8&psc=1
https://bafxpro.com/products/obdreader

+1 I've recently used BAFX Bluetooth with both "850 OBD-II" and volvo850diag. So far has worked fine in both programs.

I've also recently tested the new ScanTool.net OBDLink MX+ with both "850 OBD-II" and volvo850diag. That tool can not only be used with Android and Windows, but also works with iOS. It's a bit expensive (US$60-$100), but it also includes good OBDII software that comes with the ScanTool.net tools, *AND* it now includes free vendor-specific diagnostic add-ons (eg, for Ford, GM, etc) that might be useful with some other non-Volvo vehicles.

And I'm very satisfied with how the ScanTool.net OBDLink LX BT tool works with "850 OBD-II", volvo850diag, jonesrh-enhanced freediag and milageread. OBDLink LX BT has been my workhorse with the "850 OBD-II" app, ever since beginning to test the early versions of the app several years ago.

The BAFX Bluetooth and OBDLink MX+ have been used with my '98 S70 GLT. The OBDLink LX BT has been used on both my '98 S70 GLT and my now-deceased '97 850 T5.

[shaolinpat]

I've got scantool working in conjunction with my linux laptop. It was a little bit of a pita to get the com ports to work (sudo chmod 777 /dev/ttyUSB0 was needed).

I've also tried the 850 OBD-II, but there's something that's not playing nice (I probably have a non-reputable knock off of the ELM327. At any rate, the tool can send an email to the developer if anything doesn't work, and he got back to me in less than five minutes. He thinks my set up has revealed a bug that he's fixing in his code.

The scantool found that I now have four codes P0172, P0300, P0305, and P1310,

In addition, when it warms up to closed loop, scantool says it has an O2 sensor error.

Finally, my fuel trims are way too positive (short term and long term are around 20%).

I think a vacuum leak sounds like a place to start. Any other/better/follow up ideas?

[wizechatmgr]

I'd check for an exhaust leak after the turbo on the exhaust side or a leak after the turbo on the intake side...

[esl_97_850_T5]

When my '97 850 T5 manifested P0172 in OBDII scanning software, it also manifested 2-3-2 via the flashing LED tool. The source of my "P0172, in conjunction with EFI-232" problem was a grossly ruptured hose at the "evil elbow" on the USA passenger side intake manifold, in that cubbyhole near the alternator and underneath the thermostat and ECT. That vacuum leak was very obvious visually, and was very obvious when spraying carburetor cleaner while idling. I performed Matthew's over-the-engine, "evil elbow" port to PTC port, very-easy-to-install-hose klutz fix instead of a proper PCV system fix. The P0172 / 2-3-2 problem never returned during the 850's remaining 5 years.

It could be that your P0172 problem is separate from your misfire codes problem.

[erikv11]

The source of my "P0172, in conjunction with EFI-232" problem was a grossly ruptured hose at the "evil elbow" on the USA passenger side intake manifold, in that cubbyhole near the alternator and underneath the thermostat and ECT. That vacuum leak

Probably 8 out of 10 P0172's on P80 cars ...

[shaolinpat]

I sprayed carb cleaner around the engine. I put some down by the left side of the intake manifold (as I'm standing in front of the car), and that changed my rpms some. I really couldn't see where I was supposed to be spraying to get to the so-called "evil elbow", but was spraying where I thought it was.

I also sprayed under the top side of the fuel rail, and got quite a lot of engine reving just to the right of the fuel cap.

I'm not sure what this means, as a diagnosis. What else can I do to narrow things down/make repairs?

Thanks.

[abscate]

A smoke test is the definitive way to find leaks.

Lots of you tubs on building one, takes about a hour

I use a small air compressor and smudge sticks but it does smell like a pot party afterwards

[erikv11]

If you get a flashlight and just look at that end of the IM, you can see the nipple with the rubber elbow on it. It's not too mysterious actually. It's"line #3" in the pics at the start of this thread: viewtopic.php?t=65002

[esl_97_850_T5]

+1 Excellent thread, along w/ its t=63615 companion thread.

[abscate]

I sprayed carb cleaner around the engine. I put some down by the left side of the intake manifold (as I'm standing in front of the car), and that changed my rpms some. I really couldn't see where I was supposed to be spraying to get to the so-called "evil elbow", but was spraying where I thought it was.

I also sprayed under the top side of the fuel rail, and got quite a lot of engine reving just to the right of the fuel cap.

I'm not sure what this means, as a diagnosis. What else can I do to narrow things down/make repairs?

Thanks.

It's a sure fire sign of at least one vacuum leak.

Your fuel trims are also telling you that. If you look at the fuel trims at 3000 rpm. And they fall to a few percent, that's definitive for vacuum leak