I've had the P0327 for a little while but ignored it. I'll clear it and it will go away for quite a while, then come back randomly. I run premium gas and seem to run well.

P0150 just came up after I finished a lengthy job: Replaced upper intake manifold gasket, both valve cover gaskets, PCV valve, spark plugs with Champions, and spark wires with Magnacores. The old Bosch spark plugs were fairly fouled on the end.

Also of note, several of the snaps on my mass airflow tube coming off of the air filter housing box and connecting the two tubes, are broken of course, being worthless and foolishly designed, so the connection isn't the most solid.

Any thoughts? Why would this P0150 all of a sudden come up after this job? If it is just an O2 sensor that needs replaced, how hard is that? There's a bundle of wires sitting on the front end of the passenger side valve cover gasket that are not enclosed with corrugated plastic, could that be a problem? I'm going to get some to enclose them with.

The vehicle is running really great after these spark plug and wire replacements, noticeably smoother, more responsive, and MPG is up. Surprised at how much of a difference it made.

 

P0150 is a code for Bank 2 sensor 1 O2 malfunction.
This would be the right (passenger side) front sensor, assuming you have a left hand drive rig.
Have you checked the O2 orange plug for contamination it sits right below the rear of the valve cover clipped to the bell housing?
Oil from leaking valve covers and coolant from leaking head gaskets can cause problems if the these are full of crap.
Take it apart and clean and dry it well with contact cleaner or even brake cleaner.

Since you had everything apart you may have drip some junk on it.
I think this is the first thing to look at.

 

Thanks Steve, really appreciate the direction! I'll give that a try and post results.

 

Just some code info w/LR info.

 

Ok, so I looked under the hood and one of my vacuum lines was off. I have a 6 hour drive today that's unavoidable so I haven't been able to look at the O2 sensor yet.

Reconnected the line before I started my drive. So far no more codes, and I've been driving a bit...

 

Came back on. Shucks.

 

"on" ?, you getting eng light/does it flash? Just the new O2 code or both?
......

 

Check engine light came on, with the codes again. Now I've got all these:
P0150 O2 Sensor Circuit
P0327 Knock Sensor 1 Circuit Low
P0174 System too lean
Pending: P0159 O2 Sensor Circuit Slow Response

And this noise!!! What is this noise? https://*******/5h6W That's the rear driver side wheel, sounds like exhaust.

I've been hauling a full sized work trailer this weekend about a thousand miles total, moving my family, with these codes... No way to avoid it. Gosh.