Volvo Repair: 1998 V70 XC OBD Code P0172, volvo v70 xc, 1998 volvo v70

Question
Hi Regis!

I purchased a used 1998 Volvo V70 XC about three months ago and am so far really pleased.  The car had 84,000 miles on it, and had been dealer serviced up to about 75,000.  The timing belt was replaced at the dealer.  I've done all the required maintence since 75K.

About two weeks ago, while on a long (12-hour one way!) road trip, the check engine light came on.  After a few days, it went off on its own, but then a few days later was on again.  I read the code as 0172 (System too rich [bank 1]) and reset the code, but it came back again a few days later.  The car now has 93K miles.

A few weeks prior to this, I changed the spark plugs, but they didn't have the platinum ones in stock so I had to go with traditional and had to gap manually to 0.9mm.

What would you recommend I check next? Should I just change the O2 sensor?  Reinstall new plugs (unlikily the cause I think)?

Thanks,
Kevin Collins
happy_15010@yahoo.com

Answer
I am not familiar with the generic codes.it could be a bad O2 sensor.they do go bad often.I would need to see what the code is in volvo terms.one problem they have is oil leaks down the O2 sensor wires and the go bad.check the O2 wiring for oil in it.