Hey Scotty and gang,
2012 Chevy Cruze, 105250 miles. Today I pulled in the driveway and notice the engine light. When I parked, the idle rpm’s were going up and down. Whipped out my trusty Blue Driver and got P0171, engine running lean. Checked live data: 35% short term fuel trim and 34% long term fuel trim. O2 sensor 1 read 35.2%, but O2 sensor 2 had no reading. Is it likely the oxygen sensor 2 has gone bad and needs replacing?
Thanks
I think I should also add, the fuel pressure was at 43.5psi while it was idling during the diagnosis.
You probably also want to get a new PCV valve and check for loose or cracked connections at the intake manifold and valve cover.
On my car, the pcv is built into the valve cover. Its a pain in the butt because an easy $10 part to fix now becomes a $100 pain.
the idle rpm’s were going up and down
Check for vacuum leaks.
Good suggestion. As soon as I opened the hood, I heard the valve cover hissing away. Need a new one. Auto Zone has them i stock but Rock Auto has them way cheaper, I just need to wait for shipping.
Oh well. Life sucks, then you die. It's unfortunate that car makers use cheap, plastic PCV valves that are difficult to change out. It is, however, an important element of the emission control system and the overall function of the engine.
I have to use a couple dabs of rtv gasket sealer where the timing cover meets the valve cover. Should I snug the new cover on the. Let it sit a while before torquing it down or just let it sit on the gasket maker, wait then snug and torque?
I would cover the entire contact surface with the rtv and torque it down immediately.