Diagnostics code refuses to be read

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The Check engine light is on in my '96 Camry LE. This model is not OBD II compliant. I tried using the paper clip method across the TE1 and E1 terminals, but the thing just refuses to flash.

Umm... I should mentioned that even though the Haynes manual stated twice not to do it with the engine running, (just the key in the 'ON' position), I screwed up and tried first with the engine on. I heard the engine rev a little louder then it went back to normal. This was when I got a clue and turned the engine off, tried to read the code the proper way and it wouldn't work.

I also should mention that it may have been the gas tank cover. The CEL on this model comes on when the cover is loose. It didn't seem any different than normal when I took it off, but maybe it was. Just thought I should mention.

Other than that, I have no clue what could be wrong, and the light is still on after a couple short drives. (It came on yesterday afternoon).

posted by  JaneiR36

--It's OBD II, silly.


--of course, to find the correct diagnostics plug, remove the slide out box covering the fuses on the driver's side. It's right beside the fuses.

--Cool! Thanks! They pulled the code for me this morning and it was P0420 - Catalytic efficiency below threshold (Bank 1). Among several much more complicated causes, I've learned that this could also be caused by water in the spark plugs / wires (don't remember which). Unfortunately, my problem could be self-inflicted because I did hose down my entire engine a couple weeks ago. I'll change the plugs and possibly the wires and see if this helps any.

--Good luck!


posted by  JaneiR36

Hi all.

I've done some tests on the O2 sensors and now I need some help interpreting the results.

The voltage at the main O2 sensor (white wire, Bank 1 Sensor 1) climbs steadily from 0 V to 0.9 volts when I first turn on the car (cold). Then when the engine is hot, it fluctuates from 0.2 to 0.9 V. According to the Hayne's manual, this is proper behavior for the O2 sensor.

The sub sensor, on the other hand, only got up to .4 or .5 V and on the down turn will sometimes go all the way down to .04 V. Is this automatic cause for replacement, or could something else be wrong? Please help.

PS: I changed the spark plugs and the old ones were in fact a little wet. :oops: They'd been left in there way too long, too! The side electrode was the same color as the insulator. Both were grayish white, kinda like ash. The base electrodes were pointy towards the top, rather than just cylindrical like a normal spark plug. Other than that, no deposits on the plugs or anything. Does this point to any condition in particular? [**Edit: Denso looks like this right out the box, apparently :laughing: ]

posted by  JaneiR36

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