I just installed the new engine and EGR valve along with a few other things and i'm getting the EGR malfunction code 71. What gives???

 

Vacuum modulator?

 

Are the hoses hooked to the right places, they all look the same.

FSM EGR page for reference if your not sure:http://personal.utulsa.edu/~nathan-b...77exhaustg.pdf

 

I've believe you've mastered that nasty EGR, have you not?....."Mr. Mudhippy"...tehehehe.

 

I certainly have obtained mastery in defending MY engine against it's deleterious effects and troublesome codes.

Overall it's a pretty simple system though, even if you have to deal with keeping it in working order. Most malfuntioning EGRs require only cleaning the valve parts or tending to the rubber hoses from what I've gathered.

 

i'd remove the damn thing but since it helps keep cylinder temps a little lower i'll take it since the 3vze is prone to HG failure

 

And that pesky little modulator!

 

I would think a better stock exhaust set up would help eliminate that more.

 

Have you tested your EGR gas temperature sensor also?

 

no sir, i wasn't aware it could be tested...tell me more

already a step ahead of ya, as i finished the Y-pipe mod a few days ago

https://www.yotatech.com/forums/f116...y-turn-119799/

 

Where's mine?!!

Yeah, I saw that thread. I got one in the works for the future....IF I CAN EVER GET IT RUNNING AGAIN!!! AHHHHH!

 

I don't think the 3VZE has one. Just the EGR Valve, EGR Vacuum Modulator, Vacuum Switching Valve for EGR, and several vacuum lines ran between them and the throttle body. The ECM only actuates the VSV in accordance with the readings it gets from the Engine Coolant Temperature Sensor to start/stop the flow of exhaust gasses through the EGR valve and into the Plenum Chamber. The Vacuum Modulator adjusts the rate of that flow.


I suspect that the Oxygen Sensor is what determines whether or not the code 71 gets tripped. My guess, since I don't get that code with no EGR valve, is that the valve isn't closing when it should. Since it's new(can't be needing cleaned), that leaves improper installation/setup as the most likely scenario. VACUUM LEAK(HOSE or GASKET) or VACUUM HOSE ROUTED INCORRECTLY(PLUGGED IN THE WRONG PLACE).

Is the Vacuum Modulator new? (I was gonna assume it, but...)

 

CA (and maybe some other) models have the sensors. I checked on that long time 'go.

I'm pretty sure the modulator is not repairable. I've a used one that does work...would sell for a couple bucks, if you wanted it.

(BTW, if you don't have the sensor, the hole should be plugged)

 

I see, wonder what the heck it does, the sensor. Why for?

Testing the vacuum modulator seems like alot of work, I'd probably take the one you know is good for a few dollas just to save me some headache.

 

Go ahead and check the filter first. It's probably fine, but it's easy enough. The test on EG2-150 of the FSM is pretty simple. If it fails that, then it's bad. Blow off the vacuum gauge test....it is a pain. Unless, you're really dedicated and have a gauge.??

The gas temp sensor measures the temperature of the exhaust gases. When EGR valve opens, the temp increases, the resistance in the sensor decreases and the voltage drops. Then, the ECU knows the valve is functioning.

I've got a stash of EGR info from past and recent reading. Here's some for your stimulation: http://www.autoshop101.com/forms/h32.pdf

 

i'm gonna take a guess and say the actual temp sender that screws into the side of the egr is bad. its got 160K miles on it so why not replace it right? also my truck is running lean in open loop according to a diagnostic i had run on the runner. apparently my coolant temp. sender is goin out too...

 

You can test the EGR sensor first. They aren't really cheap.

Coolant temp sender or sensor? Makes a difference. Only the sensor will affect how it runs, of course.

 

Clever. No wonder then why I don't get that code, no have one of those. What else am I going to have to force my self to learn about these antiquated contraptions? No Mo Pleasah!! sorry, all learnin' is good learnin' truly.

 

Oops! I didn't realize he had the V6 model. I'm still learning about the Yotas/ I recently converted from a Nissan.

 

It looks like his does have one, mine don't but it's old. And I hadn't found it in any literature I had access to. Thanks thook.