intermittent CEL on 98 3.4

Last week I had the CEL come on on my way to work. Later that day it went off. I have a Ancel code scanner for my 2002 Wrangler so thought I would check for stored codes. That unit will not connect with my 98 Tacoma 3.4. I drove it for a few days and it just purrs, even when the cel was on, still running great. This morning cel back on, now off after several stops. Any ideas? Should I be checking connections to all sensors? By the way just getting ready to turn 247 thousands

Tia

 

Welcome aboard. Check the OBD11 and Tacoma port for pin damage. You have to have a code # to know why the cell is on.

 

I took a look and dont see any damage to either side, The scanner works fine on my Jeep. Had the truck in about 9 month ago for cel and running rough so I assume the port was working then This Ancel scanner says it will work with almost all OBDII ports from 96 up. So I really don't know if it is compatible with the toyota, trying to do some research on that. Whatever is triggering the cel is correcting itself otherwise the cel would stay on, correct?

 

Your scan tool should work on Toyota. Some MIL come and go EVAP and O2 sensors that are caused by leaking vacuum lines in particular. @MountainMan1989

 

Ok,until I can figure out why the scanner is not working, I will visually check the vacuum lines.

Thanks

 

Propane or starting spray on vac lines while engine idles will rev engine when sprayed on leaking vac lines

 

Forgot about that trick, thanks for the reminder. Will give it a try tomorrow.

 

I've been looking for a code scanner too, that works on my '15 Chevy and '99 Taco. From the Ancel listing on Amazon:

"Works on MOST 1996 US-Based, 2000 EU-Based and Asian cars, and newer OBD II & CAN domestic or import vehicles."

I've seen the same restriction on other OBD II port scanners too. Still looking though...

 

I get this problem right around the time I need a smog. It's always the o2 sensor. It'll come on for a day n go away for a week n come back on. Truck will run fine, no rpm difference, no stutter, no mpg decrease. I change the o2 with the Denso sensors from autozone n CEL stays off.

You need to pull the OBD2 code

 

stop by an O'Reillys and they will check the codes for free.