p0171

[dreameral]

HI, this is my first post. My Engine light came on a couple of times on a trip to Myrtle Beach. First time was at the start of the trip and I figured it was the gas cap was loose. I drove all day and topped it up with gas a couple of times. The next day it when out on it's own. On the trip back filled up again on gas and as i pulled out onto the highway and accelerated hard, the CEL appeared again. This time I had my wife take it to a garage and the code was p0171.The mechanic wrote P0171 O2 sensor on the invoice. Does this mean it's the o2 sensor or is he just guessing. I bought the car second hand and there were good records. In Jan 06 the bank 1 sensor 2 was replaced. Any ideas please.

[garagedude]

Check out the entry "WHERE'S THE O2 SENSOR" posted up the list (09/22/2007) with my post on page two that describes codes and sensors that may need to be replaced. You may have had other codes that the dealer didn't tell you about. Some places like Advanced Auto Part (?)
can read the codes for you when you CEL comes on. Info in referenced post may be of interest to you if you want to fix it yourself (a lot cheaper!).

[73mach1429]

P0171 is a system too lean code. This could be caused by several things but is most likely the MAF sensor. P0171 is tripped when Long Term fuel trim is very high. If Long Term Fuel Trim (LTFT) is high on both banks, clean the MAF. If it high on only one bank,replace the A/F sensor in that bank.