Check Engine Light

[sumpnfishy]

Original owner of a 95 4R 6 cyl with 137K miles on it. It's now a second vehicle but has got a lot of use this winter here in Indiana. Lately the check engine light comes on then goes out after 15 - 20 minutes of driving. Everything is working and engine runs normally. Took to O'Reilly autoparts and they couldn't get a reading, just kept saying downloading info. So I tried the jumper pin method I found on this site but CE light just comes on and stays on. Autozone didn't have the proper connector (they said it was too old).

My question is with something that randomly triggers the light to come on, is there a possibility of something major wrong that must be addressed ASAP or just a slowly failing sensor of some sort?

I've never had anything major go wrong so most parts are still original. Any ideas would be welcome before I have to go to the Toyota dealer (not my favorite option).

Thanks

Dennis

 

[bills86e]

Yes, open the diagnostic cover next to plenom passenger side, jumper with a paper clip the TE1 & E1 terminals, get in and turn the key to run position and count the pulses flashing. Next check the code list and repair whats wrong. Post here to confirm.
Next open the e-box (big) and pull the F1 fuse then wait 30 seconds to replace, this will turn off the CEL (check engine light).

Bills86e

 

[giro]

IMO on vehicles this age and older, the CEL can often be thought of as a "Replace the O2 sensor" light. That would be my first guess, especially if it's never been replaced.

There's other things it could be too, such as how a recent poster had a loose connection to his MAF....so it's worth getting the code and checking what it points to. And truthfully mine is at nearly 160k and I don't think the O2 sensor has ever been replaced. But I've replaced them on a couple other cars between 100k and 150k, including an Acura Legend and a Corolla/Geo Prizm. It was very unnerving being 100 miles from anything on the way to Yosemite the first time I had the check engine light turn on on the Legend.

 

[fourwd1]

A 95 would be OBD-I, so a scanner won't do anything.The OBD-I diagnostics Toyota report a lot more then O2 sensor info, but of course not nearly as much as OBD-II.