I am having issues with my truck and upon turning the key on, I see lights for "maintenance required", Battery symbol, and one other (can't remember off the top of my head), but wondering if the check engine light is different from "maintenance required" and if so what "spot" in the dash it would be in. In the cluster it looks like there are two areas for "warning light", one to the left upper side of the cluster with 2 rows of 3 possible lights and the same on the upper right side. Could someone check this for me please. I'm wondering if the check engine light is supposed to be on (hence poor performance on highway) and it was either burnt out or disabled.

Thanks,
Chris.

on my 91 when i turn the key on i have battery light, oil light, brake light, seat belt light, and the maintenance required light. while i was looking through the service manual last night i did find that i was supposed to have the check engine light come on too, but like you mine does not, im thinking this weekend i will rip in to it and see if the bulb burned out or is disabled. i think it may be the latter because while i was in school (for automotive technology) i did the test light thing to get the codes out and found that i needed a new O2 sensor (which would turn the light on) the check engine light on my truck, speedo cluster no tach, is between the maintenance required and brake lights on the left above the fuel gauge. not sure how different it is on your truck but i hope this helps

Hi. There is a maintenance light in our trucks to remind us when our timing belt needs replacing. When you do replace the timing belt, there is a rocker switch under the cluster behind the right block off plate under the cluster. Just slide the switch to the opposite side, sliding it one side, then back would turn it back on. Hope this helps.

The 89 does not have a check engine light - no Mitsu I know of with a carb has one. The computer for the carb is not that sophisticated and it was not required back then. The maintanance light is a mechanical switch off the back of the speedo as previously mentioned.

I guess the question is, if the O2 sensor goes out is there any way to tell? Can it be tested? I am fighting a driveability issue and all I have left are carb ($500) and O2 sensor. The truck seems to lean out at high rpm and load. I have done the general maintenance (timing, replaced cap, rotor, wires, plugs, both fuel filters, fuel pump, PCV valve, and carb cleaned the carb as best I can with spray clean and two cans of seafoam run through the tank). All I can think of now are bad carb (in the secondary) or something causing it to lean like TPS sensor or O2 sensor....

Thoughts? I don't want to have to buy a carb if I don't have to. 147K on the clock.

Did you check all the hoses under the hood, especially in the control box on the drivers side inner fender? If the lines are off or split in that box, it will lean out under load and lose power; my 88 with the 2.6 did the same thing and the hoses in the box were the culprit.