Does sound as a faulty O2 sensor, pending on vehicle make "bank 1" can be either side of motor. Wire connection may of come apart, just happened to somebody. Water in gas not sure, seems would affect entire motor. Regular dry gas should work, all it does is dissolve the water so it mixes with fuel and can burn.

Hi test gas does nothing either except to stop engine from igniting on compression stroke like a diesel. You hear engine pinging or worse knocking. Yes, will wreck engine.

Again, just what I would look at myself, don't see an abundance of replies here, but never do.

Appreciate your info Rich!! I seen a Youtube video that said it could be air coming in through valve cover gasket, which made since because I noticed this was an issue even before the engine light. I had planned on replacing anyway so will see if that clears the error. Drive over 60 highway miles over the weekend and car drove fine!!

Your welcome W23. Would be nice to view a variety of other answers not so old as I also get ideas and pick up on things myself.

Never gave leaky valve cover gasket leakage a thought for PCV trouble. Myself, I've found loose bolts on those, oil leaks and such. Used to use RTV silicone to make on site gaskets for those and one time used a combo of actual gasket and RTV. Never leaked again; but I wonder if spraying with soapy water could work for those to detect leaks same as to find a tire leak? Never tried on a vacuum only with pressure, hmm. Probably not noticeable for bubbles with pulling air in.

https://cimg0.ibsrv.net/gimg/www.bui...505c9ed684.png
is this where i put the glue?