P0159 Won't Clear

3002 tii · 01-23-2016, 12:00 PM

I had error codes P0420, P0439 and P0159. I concluded my rear o2's were failing so I replaced both and then cleared the codes with INPA but P0159 still appears. I know for incomplete readiness you have to drive certain number of miles for the drive cycle to reset, but is that the case even for regular codes?

inTgr8r · 01-23-2016, 06:30 PM

Not sure on this one whether it requires a drive cycle to clear.

There are other potential causes.
- Faulty Rear Heated Oxygen Sensor Bank 2
- Rear Heated Oxygen Sensor Bank 2 harness is open or shorted
- Rear Heated Oxygen Sensor Bank 2 circuit poor electrical connection
- Inappropriate fuel pressure
- Faulty fuel injectors
- Intake air leaks may be faulty
- Exhaust gas leaks

I would wait on the drive cycle before chasing other things.

01-23-2016, 12:00 PM	#1
3002 tii Lieutenant General 2280 Rep 12,565 Posts Drives: Z4 M, X5, GX460 Join Date: Apr 2008 Location: CT iTrader: (99) Garage List F15 X5 xDrive35i [8.75] E86 Z4 M [10.00] F10 550i (Retired) [9.17] F25 X3 xDrive35i (R ... [9.43] E82 135is (Retired) [9.50] E85 Z4 M (Retired) [9.41] E90 328i xDrive (Re ... [9.25] E86 Z4 3.0si (Retired) [9.20]	P0159 Won't Clear I had error codes P0420, P0439 and P0159. I concluded my rear o2's were failing so I replaced both and then cleared the codes with INPA but P0159 still appears. I know for incomplete readiness you have to drive certain number of miles for the drive cycle to reset, but is that the case even for regular codes? __________________ Follow for latest mods
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01-23-2016, 06:30 PM	#2
inTgr8r Lieutenant General 2426 Rep 11,667 Posts Drives: M2 Comp Join Date: Mar 2006 Location: Toronto iTrader: (10)	Not sure on this one whether it requires a drive cycle to clear. There are other potential causes. - Faulty Rear Heated Oxygen Sensor Bank 2 - Rear Heated Oxygen Sensor Bank 2 harness is open or shorted - Rear Heated Oxygen Sensor Bank 2 circuit poor electrical connection - Inappropriate fuel pressure - Faulty fuel injectors - Intake air leaks may be faulty - Exhaust gas leaks I would wait on the drive cycle before chasing other things. __________________ '21 M2C Hockenheim Silver '18 718 Cayman S Lava Orange (sold) '13 E92 M3 Santorini Blue (sold) '07 Z4 M Coupe Alpine White (sold)
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