Lean both banks, with random Rich codes - HELP!!
I have a 2008 LR2 3.2L with a hair over 90k miles. I have two codes keeping me from passing state emissions - P0171 and P0174. Those codes are persistent, and appear within 10 miles of being reset. I also get random P0172 and P0175 codes. Not sure how I am getting both lean and rich codes, but it is.
My Fuel Trims seem to only be lean at idle, and even out to at least acceptable ranges above 1500RPM. So I would assume vacuum leak. Dealership has not been able to find one. Thus far I have replaced the MAF sensor, Air Filter, FRP Sensor. The dealer replaced "Vacuum diaphragm"? and the PCV Oil Trap. I left the battery off overnight after the dealer repairs to reset LTFT's, but codes were back within 20 miles.
I am still leaning towards a vacuum leak due to the trims, but have not been able to find one either visually, smoke tested, or carb cleaner tested. I have it scheduled to be back to the dealer on Monday, but was wondering if anyone else has had this persistent CEL issue? I have already paid about $700 to Land Rover of Salt Lake, and my LTFT's are still pegged at 24 at idle.
Thanks in advance!