The CEL came on again. I pulled the codes and a 71 showed up. I must've misread it the first time (DUH). I've pulled a vacuum on the EGR valve while idling, and she basically dies. So, what's doing? Is the EGR modulator the culprit? I'm guessing the EGR could still possibly be the problem since the CEL doesn't stay on all the time. Is it supposed to? I don't know. I'm guessing it's possible that the EGR valve is hanging up every now and then, thus throwing a code. What else should I test and how?

Thanks,
David

Cali-smog model? Does the EGR have a sensor on it with an electrical connection? My wifes 89 Celica (3SFE) is cali-smog and when it threw a 71 (shares the same codes as 22R-Es) I got pissed and hit the EGR gas temp sensor with my "metric crescent wrench", reset the codes and things have been fine since. Non-Cali smog engines luckily dont have to deal with the code 71. Might be the modulator-but I would think possible wiring to the sensor issue first.
~Darin <img src="/forums/images/graemlins/baby.gif" alt="" />

Darin,

You are correct... it is Cali-smog legal. So where is this sensor? And what exactly did you do to it?

If that doesn't solve it, how can I test the modulator to see if it's malfuctioning?

Thanks,
David

I honestly cant help you on testing the modulator-never had to go that far...and with spare parts inventory I have, just swapped things like that out if I thought it didnt work right. Location of this sensor is somewhere on the EGR tube leading to the back of the plenum...follow the wires. Cant find a picture showing location at the moment. But I did find this at autozone.com :

EGR Valve Thermo-Sensor

Disconnect the electrical lead which runs to the EGR valve thermo-sensor.

Remove the thermo-sensor from the side of the EGR valve.

Heat the thermo-sensor in a pan of water to the following temperature: 260?F.

Connect an ohmmeter, in series with a 10&#969; resistor, between the thermo-sensor terminal and case.

With the ohmmeter set on the k&#969; scale, the following reading should be obtained: 2.55K&#969;

Replace the thermo-sensor if the ohmmeter readings vary considerably from those specified.

To install the thermo-sensor on the EGR valve, tighten it to 15-21 ft. lbs.


CAUTION

Do not tighten the thermo-sensor with an impact wrench.




Checking the EGR Vacuum Modulator

Tag and disconnect all hoses leading form the vacuum modulator.

Remove the vacuum modulator.

Unscrew the vented top plate and remove the filter.

Check the filter for any contamination or other damage.

Clean the filter using compressed air.

Installation is in the reverse order of removal.


Hope this helps you some. When I say that I hit the EGR valve with a wrench I was dead serious. Now if this knocked some carbon off the plunger or just jolted the connector enough to make a better connection I dont know. Start with the wiring, make sure its not damaged then move on from there. If I find the picture I was looking for I'll pass it along.
~Darin <img src="/forums/images/graemlins/baby.gif" alt="" />