rough idle p1273 code.

Question

2004 Infiniti g35 sedan, rough idle p1273 code. Rpms fluctuate as its shifting down gears, also rpms jump up a little while foot off gas idling

Answer 1

The code is for the bank one O2 sensor. This is the first O2 sensor on the side of the engine closest to the firewall. This can cause the issues because it helps make the fuel mixture on that bank. If it's reading wrong it will produce the wrong fuel mix and that will give you issues. It can also be a sign of some other issue. Perhaps an exhaust leak or intake manifold gasket leak could cause this code as well.