OK... I got a new EGR valve (and gasket) today, and put it on. Let the codes clear while I was doing it too.

Took her for a test run, and after a brief 'relearning' period, the old truck started running great. I drove it a long time, all over town just to enjoy the smooth ride, increased power, smooth coasting, etc.

When I got back home, I checked for codes - still getting the 33 code!

I'm gonna pull what's left of my hair out... The truck runs so much better, and the only EGR component left to replace is the position sensor. Maybe the sensor is bad too? Since the code states that it can't detect movement, I'm assuming that the sensor isn't detecting the movement that is occurring... because the valve is definitely moving now.

...Another day another $30.

 

Good grief! You certainly are persistent!

If you opt to change the position sensor - be sure to get the right color - IIRC, the options are grey and white.

Also, don't overlook the possibility of a wiring or other connection problem between the sensor and the computer. My favorite has been a connector sleeve pushed back in the connector.

Good luck. If there's ever been a problem that deserves to be solved due to sheer effort - this is it.

 

It's killing me... But at least it runs right, even if it doesn't know it!

I've been through everything - connectors, vacuum lines, vacuum fittings, etc. I've replaced the solenoid, the valve, a couple of vac fittings... The only things left are the sensor, and the tube running in from the bottom of the valve. (admittedly, I have no idea where that stupid tube goes, I assume the exhaust somewhere back there)

It's not clogged up in the vertical part of the tube near the valve, but who knows what's on down there? I would think that the truck would still drive like crap if it was a clog in that tube... I can't imagine that causing the code I'm getting either.

Either way, I'm gonna buy a sensor in the next day or two and hope it finally goes away.

 

I like to test and make sure parts are bad before changing them instead of just changing everything, but it looks like that would have worked fine for you. At least you know the parts were bad before you changed them. With the EGR stuck partially open and not moving the sensor must also be stuck. Maybe you can try unsticking it, checking it to see if it can move, or just change the damn thing and call it done.

 

That's the crazy thing about the sensor - it moves very smooth. I'm so confused and frustrated that I don't even care anymore. I'm gonna pick up a new sensor and get this over with.

Remember how I couldn't figure out why the old EGR valve wouldn't close? I took the old dremel and dissected that booger - it had crud way up in there, well beyond where any cleaner would reach.

The good news is, I've learned a lot from all this. It's fun (in a sick sort of way) to think these things through and explore the options.

 

Glad you're having fun. One other thing, you did have the sensor unplugged and plugged back in a lot during this whole thing. You may want to check the connector for damage, pushed out wires and tightness. Also check the condition of the wires, sometimes when things are taken apart the wires don't exactly lay where they used to and might rub in a bad spot. You can also check the resistance of the sensor to see if it works.

 

...maybe I'm beyond having fun. Last night the truck ran smooth and great, and I was excited. Today, the first 10 minutes driving to work it was like driving on a washboard again - then it smoothed out... driving home, same thing.

I checked codes to see if something else fell apart, and got the same old 33, along with the O2 sensor code again. Nothing new...

Is the old girl getting confused with the EGR working but the sensor giving inaccurate info? I checked the connector and wiring again, and it's all good. I sure hope that a new sensor puts an end to all this... I had to order one, so it will be a day or two before I know for sure.

 

Fix what you know isn't working, the sensor, and then go from there. There are a few other tests you can do, which I've never done. You can initiate the Output State Diagnostic Mode. After continuous codes are displayed (engine NOT running) press the gas pedal. Each time the gas pedal is pressed thereafter, all output actuators will change state (off to on, on to off). To discontinue the test, remove the jumper at the self-test connector.

Then there's a wiggle test. Install the jumper wire. Turn the key on, remove the jumper wire and immediately reinstall the jumper wire. This is now Continuous Monitor test mode. Carefully wiggle, tap or move any suspect wiring to a sensor or output actuator. If a problem exists, a code will be stored for that particular component.

You can also do an Engine Running Continuous Monitor test. Start the engine and allow it to idle. Install the jumper wire, wait ten seconds and remove the jumper wire and reinstall the wire. This will enter Engine Running Continuous Monitor Test mode. Carefully wiggle, tap or move any suspect wiring to a sensor or output actuator. If a problem exists, a code will be stored for that particular component.

Have fun!

 

I have the sensor on order, so once that's here I'll swap it out and cross my fingers! Hopefully it'll be here before the weekend.

Thanks for the additional testing info - that's a lot to chew on... I hope I don't have to go through all of that, but at least the info is there if this little journey isn't over yet.

On the bright side, I feel confident that I haven't replaced parts that were good. I feel like I've proven to myself that each component has been faulty before I replaced it. I might be wrong, but at least it makes me feel better!

 

I'm sure the parts you changed were bad. Solenoid- no vacuum out when energized, not working. EGR valve- stuck open, crapped up inside, no good. No signal from sensor- you know the other parts are working, they're brand new.