I am getting a p0170 code from my generic obd2 scanner that I keep in my car for emergencies. It's showing me a fuel trim of about +12.5%. Engine was running fine and idling fine so I didn't make it a super priority at the time ( only about 2 weeks.) However, today leaving work, my engine idle was struggling to stay steady and dropped to 500 and was sputtering so I shut the engine off, waited a few seconds and started it up again, and it idled fine at about 650-700rpms. I started driving home and at the first stop sign I went to accelerate and my car could barely move and started sputtering a bit again. I pluged my scanner in to read to fuel trims, since it cant read the 02 voltage from my volvo, and the short and long term were both stuck at +25%. After 1 more stall at a red light getting onto the highway, I was able to drive home no problem and the LTFT lowered down to 9.4% by the time I got home, still lean. So I plugged in my dice unit to read it on vida and I got a codes that said air leak between the turbo and the throttle. I can't visually see any leaks or hear any and I plan to do a smoke test tomorrow. Fuel pressure is fine at 400kPa, boost pressure seemed low even though I was just revving at idle, it would barely break past the ambient air pressure. Again, dont hear any leaks or see any. PCV system has been done recently, typical tune up, all filters spark plugs, the goodies. Now pulling up a graph and looking at the front 02 sensor voltage, it stayed steady at about 1v which is weird, but its lean so sort of makes sense to me, but when I give it some gas, it stays the same and spikes up shortly after I let off the throttle, as far as 16volts. In vida it does not say the unit for the 02 sensor but I would assume its volts. I have never seen something like this. Any thoughts or help? Vida codes that relate to my issue are the following: ECM-212C, ECM-21EC, & ECM-640D. My 02 sensor was replaced within the past 6 months, bosch sensor so it was oe, but when I plugged it in, I couldnt lock the connector in using the level because it didnt line up to the new sensor even though it plugged in fine, so I threw a ziptie around it to keep it plugged in. 5 wire sensor.

 

I have learned that volvo uses a wideband o2 sensor for fuel trim measurements which means that the value I am reading is a Lambda value, not voltage. ~1 is normal range and fluctuates up and down based on the trim.

Smoking it this weekend now, should see where the problem is that way.

 

If anyone cares, there was a nice hole in my intercooler pipe (from the cooler to the throttle body) on the corrugated part