On my 2000 Lexus IS200, I replaced p0135 an then p0155 and p0171 showed, why?

Question

On my 2000 Lexus IS200, I replaced p0135, and then p0155 and p0171 showed, why? What is wrong?

Answer 1

P0155 is for bank 2 sensor 1 oxygen sensor

and P0171 is for bank 1 System Too Lean Bank 1 which means there is too much air not be acounted for.

Check for intake leaks and exhaust leaks, you can also clean the mass air flow sensor with mass air flow sensor cleaner. You can also replace the spark plugs if you have not done so (since a misfire can cause these issues)

disconnect the battery for 30min or so to reset the computer.