Hello all, I hope you can help me.

I recently inherited an '87 4Runner SR5 4WD and everything's great, except for one thing. I can drive the truck no problem without the AC, but once I turn on the AC, the Check Engine serivice light turns on. Also, it turns on at random intervals. Sometimes after about 3 minutes, sometimes after 30 minutes.

I make sure to monitor the guages, and the truck is well within operating parameters. Oil is full, no funny sounds that a 20 year old truck wouldn't make.

Anybody have any suggestions or possible solutions?

Thanks!

 

My first guess would be the O2 sensor.

 

as soon as the light comes on short the pins and pull a code.

 

Not to sound ignorant, but what do you mean by shorting the pins? I have the service manual, but it doesn't tell me anything is wrong. So what pins do you mean?

Also, I'll check the O2 sensor.

thanks

 

you can cross 2 pins with a wire to jump he codes your manual should have a section on how to jump or dump the codes. and what every code is

 

http://www.4crawler.com/4x4/CheapTri...CheckConnector