Hello all,

I have an intermittent code 5 come up in my 1986 4Runner 5sp with a 22RE. It has only happened twice, both times on the highway when going up steep grades, 4th gear 3700rpm sort of hills and nearly floored. The light will come on for 30 seconds up to a couple of minutes and then go away. The first time was in December while driving it to AZ fro CA when I bought it. It happened twice today climbing up to Flagstaff.

I'm out of town and it is mostly downhill going home so I won't fret it. I'll change out the O2 sensor when I get home. Hopefully that is all it is, but I'm not sure.

Question 1: Is the sensor back to normal once the light goes out? I'd hate to be running lean/rich all of the time. I think everything is back to normal once the CEL goes out.

Question 2: The 4Runner runs great I got 25 mpg today driving 70 mph with the AC running. If the o2 sensor doesn't fix it, I'm thinking that I'm running lean on these steep grades. My list of stuff to check would be in the fuel delivery side. Other than the pump and injectors any other diagnostics I should run? I don't like throwing parts at a problem.

Thanks for any feedback. Flagstaff is so much nicer than Tucson this time of year.

 

The CEL didn't not come back on the rest of the trip back home. I was getting 20+ mpg grieving in the mountains with the AC on.

I'll check the O2 sensor, but I really don't think that is it.

 

Im tracking a Code 5 issue now...

 

Mine has not come back.

 

On intermittent codes, the most error from my experience is a vacuum leak some where. Cracked hoses, one not hooked up somewhere...