Code 28 / High Altitude (1 Viewer)

[JPC]

I have a 1989 FJ62 throwing a code 28 (O2 sensor #2 fault) . I live at 9000 ft and drive between 5000-9000 ft. The engine seems to run fine, mileage 11 mpg, some gas smell in exhasut. Is is possible that it is defaulting to a lean mixture with the bad sensor? Is the sensor worth replacing or chasing down connector problems, etc?

Any thoughts appreciated...

 

[LAMBCRUSHER]

yes and yes. use high quality O2 sensors.

 

[Kynot62]

A quick trip to a shop with the computer to read the workings of yours would be money well spent. The sensors on a 62 aren't cheap and you don't want to throw money at parts that may still be good

A code 28 doesnt guarantee that the sensor is bad. It could also be the ECU, the circuit, the wiring.... It gives a good mechanic a starting point to look for the problem. Sadly it takes some expensive equipment to actually find the culprit

Tony

 

[Trapper50cal]

could it also be the HAC? High Altitude Compensator? I know that handles advance in the timing but could it effect how complete the burn happens in the cylinder?