My engine light is on.
Fail message :
bank 1 and bank 2 readings bad
- replaced all 4 O2 sensors same fail codes ?
Also once in while maybe 1,2 a month my car smokes blue smoke for 20 seconds and stops
Specially if I reset the error codes.
The bank 1 & 2 faults should have a fault code, indicating where the problem should be. A vacuum leak can cause a lean problem on both banks. Check the intake pipe hose for tears, allowing air to get in after the MAF. The big hose, also check the 2 CCV valves on each valve cover. The blue smooth is from the valve seals, on ly a thicker oil will slow that down, without replacing the valve seals.
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