po300 code, interesting possible explanation?

[SP543]

While driving at around 9000ft on the highway in CO my car started going into limp mode and the check engine light came on. I would pull over, wait 2 min or so, start back up and everything would be fine for 2 miles or so and would repeat. Once I got to the exit I let it sit for 25 min. or so and it after it was fine for the rest of the ride to where I could scan the code, it was the random misfire code. I shipped this car from sea level and did the drive from denver to loveland pass a few days later with minimal driving in between, is it possible the MAF had not yet responded to the decrease in o2 and developed the misfire? After clearing the code and driving around a bit at elevation it has not yet repeated itself and have not had issues since. Any thoughts?
Thanks

 

[ccapehartusarmyINF.(ret)]

yes at 9000 ft above sea level atmospheric pressure is only like 10 psi wich means the air is much thinner and in order to maintain a 14:1 air fuel ratio atmospheric pressure needs to be roughly 14.7 PSI

---------- Post added at 05:26 PM ---------- Previous post was at 05:20 PM ----------

so the ECM needs to adjust the tfuel trim accordingly becuase at that altitude yer air fuel ration would get very lean

 

[SLCHOE]

for those following this thread I tried today carb cleaner around the intake, no fluctuations in rpm so I don't suspect a leak. I also took out the #8 fuel injector, It really did not look bad but I cleaned it best I could and put it back in. with no results. still blinking ses light the only thing I have not done is use the old screw driver to listen to the injector is there anything I could be missing? ive heard a bad battery can have some affect is this true?

While driving at around 9000ft on the highway in CO my car started going into limp mode and the check engine light came on. I would pull over, wait 2 min or so, start back up and everything would be fine for 2 miles or so and would repeat. Once I got to the exit I let it sit for 25 min. or so and it after it was fine for the rest of the ride to where I could scan the code, it was the random misfire code. I shipped this car from sea level and did the drive from denver to loveland pass a few days later with minimal driving in between, is it possible the MAF had not yet responded to the decrease in o2 and developed the misfire? After clearing the code and driving around a bit at elevation it has not yet repeated itself and have not had issues since. Any thoughts?
Thanks

yes at 9000 ft above sea level atmospheric pressure is only like 10 psi wich means the air is much thinner and in order to maintain a 14:1 air fuel ratio atmospheric pressure needs to be roughly 14.7 PSI

---------- Post added at 05:26 PM ---------- Previous post was at 05:20 PM ----------

so the ECM needs to adjust the tfuel trim accordingly becuase at that altitude yer air fuel ration would get very lean

That's not how a MAF works. MAF's don't detect O2 at all. MAF's detect airflow / volume by heating a small filament of heated wire and monitoring the voltage needed to keep that filament at that pre-determined temperature as colder air intake passes through it.. More air = more cooling = more voltage needed to keep the wire "hot" (at the same temp). That voltage difference is converted into g/s by the ECM using that voltage signal.

From your symptoms, I'd check your spark plugs.

 

[ccapehartusarmyINF.(ret)]

yes i fully understand how a MAF works wich would reinforce the explanation higher altitude=less air (if youve ever spent any time at high altitude like over 6 or 7000 ft everything you do is exhuasting )

 

[ccapehartusarmyINF.(ret)]

for example back in the day of the carberator and the snowbirds came down lower altitudes for the summer had to have there carbs re adjusted and vise versa
becuase carbs unlike electronic fuel injection had to be manually adjusted for the change in atmospheric pressure