Check this out! My check engine light only comes on in a particular location that I travel. I can wait a few days or even a month and when I travel through that particular area it lights up. It stays on until I clear it by removing the EFI fuse. The code it sends is O2 sensor faulty. I have since replaced the O2 sensor only to have the same result. I haven't checked the codes recently, but most likely it's the same. Any suggestions or ideas?

 

Stop traveling through that area...
hehe!!! sorry I couldn't resist.

 

If it keeps happening in the exact same area, it MUST be some type of EMI/RFI issue. Do you notice any other interference such as radio noise? Put the radio on AM before you drive through that area again and see what happens. It's a crude and limited method of detection, but the AM band is very susceptible to various emisiions.

 

i had the same problem. it happened twice going up a mountain towards my house. i finally took out my k&n filter, cleaned the MAF sensor again and reset the codes and it hasn't come back on since (one week now). could a change in altitude have something to with it?

 

about this location, i take it your travel to it within a certain timespan, or the light comes on when u reach a certain amount of mileage, or is it just that area?

 

i drive up this mountain six days a week usually in the evening. i don't notice anything with the mileage.

 

Tell us about this "area"........is it area 51? This could have something to do with it.

Location, altitude, geographic features, temperature, any obvious differences with this place compared to the other places you drive.

Personally I can imagine how radio frequencies could affect solid state electronics. It is more likely that this area is of high altitude, high engine load, wet, Hot, etc. Something about this place causes the code.

Strange example, Ford had this same problem with expeditions but only in hot climates. Turns out the evaporator was droping cold water droplets on the oxygen sensor when the AC was on. This resulted in thousands of bad O2 sensors.

 

The area I'm driving through is a flat highway stretch no elevation change. It does run along a river and across the river is a furniture plant. It seems to do it under acceleration or cruising. My A/F meter fluctuated funny one time, but that's it. The engine codes the last time were 31,41,71. Odd combination if you ask me. O2 sensor has been replaced. TPS has been checked with an ohm meter and the AFM has been checked.

I have some mods which include a Jacobs ignition and coil, K&N fipk,3" inch intake tube,AFM adjustment (2 teeth),ECT mod,header,and 2.25" exhaust.

 

I was just about to say that, lol. If you have FBI/CIA agents in the bushes at your house at night, you have probably found a new government facility that you should not know about. Just remember, now your phone is tapped, your tv line is tapped, internet connection is tapped, email is being read, you are being followed wherever you go (its that black suv two cars behind you). Hey this post on yotatech is being read, so now its probably two black suv's lol

 

Now I'm getting paranoid!