Emission maintenance light

[tugboat95]

So this popped up today while driving to work this morning. Went off by the time I got there but lit up and stayed for the drive home. I haven't lifted the hood yet, truck drives fine. 112k miles on original engine and exhaust is all original. Redid head gasket and new Bosch injectors 6 months ago.

 

What's the most common causes off this light? Vacuum line somewhere, O2 sensor, clogged catalytic converter? Who do I need to look at? 89 Renix 6 cylinder with 5 speedanual.

 

89 Comanche

Eliminator

2wd

4.0L

5 speed PukeGoat

Factory Original

 

 

 

[fiatslug87]

It's just a light that triggers at certain mileage (80k???) to change the O2 sensor but does not mean anything is wrong. I recall a write-up on resetting it but most people just remove the little control box.

[Eagle]

It's nothing but a mechanical timer. There are no sensors that trigger it -- it's a reminder to replace the O2 sensor.

 

[tugboat95]

I can live with that. Maybe I'll change them
...one of these days.

89 Comanche
Eliminator
2wd
4.0L
5 speed PukeGoat
Factory Original

[Pete M]

if you unplug the box, the light will go off.   it's a clearish little box with a bunch of gears in it under the dash on the drivers side.

[GrizzzzBear]

I have the same Issue.

 

What Box & Where is it??

[fiatslug87]

Under driver side dash.

Emission timer:

 

[fiatslug87]

Here's the write up on resetting if you want to go that route.

https://nickintimedesign.com/renix-emission-timer-teardown/

[tugboat95]

I've seen that box under there. And wondered what it was. I'm going let everything ride right now. All projects are on hold til I get my garage built. Maybe by spring I can rip drive train out and send the body off to be painted. Then put it back together piece by piece. I want to Stroke it but my end vision is factory original. But I've already converted to an open cooling system.

89 Comanche
Eliminator
2wd
4.0L
5 speed PukeGoat
Factory Original

[GrizzzzBear]

On 8/7/2021 at 11:11 AM, fiatslug87 said:

Under driver side dash.

Emission timer:

 

Thank You. I really appreciate the pic.