1992 740 SW B230F with 221 OBD Code Set

[billofdurham]

Welcome to Matthew's Volvo Site.

Usually the checks for the 2-2-1 code are inlet manifold for leaks and fuel pressure. Has your fuel consumption increased or have you experienced a drop off in power since the code has appeared?

On a 3 wire sensor 2 wires are for the heater and the 3rd is for the signal. One heater wire will read battery voltage while the other, which is the earth (ground) may read a very low, or zero, voltage. The signal wire should read between 0.1 volts to 0.2 volts with a cold engine running. When the engine has been running for over 20 minutes that should fluctuate between 0.1 volts and 0.9 volts. I can't give you the wire colours as different makers use different colours.

If the sensor has been spliced into the wiring check the splices. Bad joins can cause trouble.

The holes in the exhaust after the sensor shouldn't affect the reading. A catalytic converter which is starting to clog will cause a noticeable drop in fuel economy, poor high speed power, rough idling or stalling.

Bill.

[girlbunny]

It probably isn't this, but I thought I'd offer my minimal experience. My car had the 2-2-1 code (and others) which pretty much cleared up once the Mass Airflow sensor was cleaned. It's a darned cheap and easy to fix issue if it's that! Of course my actual issue was a relay, but it evidently had other problems as well, which were fixed by that clean. Hope that helps

[billofdurham]

Better late than never.

Thank you for the update and happy motoring.

Bill.