Weird codes on a 2001 S40

Discussion in 'Volvo S40' started by drowland1967, Mar 4, 2008.

  1. drowland1967

    drowland1967 Guest

    I've for a 2001 S40 with around 60K miles on it...

    Been a great car.

    Anyway, the battery was starting to have trouble starting the car on
    cold days. I got a new battery from Napa. After replacing the batter
    the following happened.

    With 20 miles or so the Check Engine light came on. The car seemed
    very sluggish.

    I stopped by AutoZone. They scanned the codes for me. Following is
    what I got:

    P0171....System too Lean (Bank 1)

    P0172....System too Rich (Bank 1)

    So how is it too lean and too rich?? Did the computer try to make a
    change and over compensate or did having the battery unplugged reset

    Thanks for any help or suggestions.

    drowland1967, Mar 4, 2008
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  2. drowland1967

    richgannon12 Guest

    what did you get as a reply? I have a similar situation with a C70 2001
    richgannon12, Mar 28, 2008
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  3. drowland1967

    drowland1967 Guest

    No replies yet...

    I did have a little more info. I was getting the oil changed the
    other day. The guy there offered to hook it up to their code
    scanner. It was a nice one. He was able to see the voltage coming
    off of the O2 sensors and the MAF sensor. You could see the O2 Sensor
    voltage changing. The MAF sensor voltage wasn't changing at all. he
    said this seemed to suggest it was the MAF sensor that was bad... I
    plan to swap it, but I haven't had time.

    Does anyone know what the MAF sensor should look like on a scanner
    like that?

    drowland1967, Mar 28, 2008
  4. drowland1967

    drowland1967 Guest

    OK, I changed the MAF sensor. The car seems to run a little better.
    The Check Engine light is still on. It still doesn't run like it did
    before. Not sure what my next step should be...

    Any ideas?
    drowland1967, Apr 16, 2008
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