Hey guys I do have a Dmax04 but my question is on an Impala 2004 SS

I keep getting check engine codes PO171 and PO172 which is fuel to lean and fuel to rich, both are on bank 1 which is the left side. I clear the codes each time and have played with different fuels etc. but keep throwing codes any ideas on what the problem is and how to fix?

Thanks, Jumper 357

vacum leak or o2 sensor?

The full message is: Fuel Trim,Bank1 System too Lean. "Fuel Trim" indicates that the problem is at idle. Things that can cause this are vacuum leak, O2 sensor, and MAF sensor.

does it have a k&n air filter.

Does it have any aftermarket air filter? If it does a possible problem may be over oiling on the filter media which can then be transfered to the MAF sensor wire. The oil gums up the wire and can give inaccurate readings. If it's not too bad a Q-tip and alcohol can clean it but be very careful you don't press really hard. Other than that the other posts seem right on with the Vacuum leak and 02 Sensors.
JP