Nissan Murano affected by change of altitude

I have an 04 Nissan Murano and live in Texas. I travel to Colorado 5 or 6 times a year. Every single time I do, the check engine light comes on. I was told it is due to the change in altitude and the computer needs to be reset when I get back to Texas. I find it difficult to understand why and what I can do to eliminate this issue without buying a different car. Both catylitic converters have been changed as the car used to lose power when going to Colorado and stop. I had to shut the car and wait 10 minutes before restarting. Now just the check engine light comes on but the car no longer loses power.

 That CEL (check engine light) is just a kid in class waving her hand trying to get you attention because she has the answer. You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code (like P0123) not just their translation into English and post it back here. 

 Your octane requirement changes when you go up or down in altitude. What octane are you using and what octane does the owner's manual recommend?  Does it have a variation in that recommendation for high altitudes? 

Note: Higher octane is not better, it is different.  You car does best using the recommended octane.

You should not need to “reset the computer.” There’s something wrong with your car, obviously. Do what Mr. Meehan suggests, and have your “codes” read.

That’s not true, by any stretch of the imagination.
If it was true, then every single Murano in the Rocky Mountain Region would have a CEL on, and I can assure you that isn’t the case.

There is a procedure you can use with the ignition switch and the gas pedal on Nissan’s to pull the code without having to go to Autozone, but it’s slightly tricky.

Hop in the Driver’s seat.

Turn the ignition key to the ON Position, or if you have the push button ignition, Press the Start/Stop button twice to put it into the on position, but do not press the brake, or the clutch, otherwise the engine will start.

After it is in the ON position, count 3 seconds.

Now, within the next 5 seconds, you need to floor and release the accelerator pedal 5 times.

After the 5th release, count off 7 seconds.

After the 7th second, press down and hold the accelerator pedal. After about 10 seconds, the SES light will turn off.

Make sure you have a pen and paper handy at this point.

Release the accelerator pedal at this point, and the light will start to blink.
Slow flashes indicate the first number of the 4 digit code, faster flashes indicate the other 3 digits.

There will be a pause of about 1 second between each digit of the code.

10 flashes = 0, 1 flash = 1, etc…

A code 0442 would be:

10 long flashes
1 second pause
4 short flashes
1 second pause
4 short flashes
1 second pause
2 short flashes
1 second pause

Let us know if you can get the code that way, and what it is.