Code 71 EGR. Where to look/fix first?
 

I've got a code 71. EGR temp too low. I'm wondering where is the best place to look/fix first. I know it will be a PITA to replace all the EGR components, and it looks like it could get expensive, also. Any suggestions?

When i had code 71 i just rook off all the EGR components and cleaned them. Unplugged the battery toreset the ECU and its been fine so far.

No sense considering replacing any parts without troubleshooting. It could be as simple as a bad temp sensor. Get into the FSM on this site and check what it tells you to check. Could be as simple as a bad modulator valve.

Ok, I'll check that out. If it makes any difference, I've had trouble with this code ever since replacing the headgasket.

Was it the right side head gasket? If you had that right head off I'll be you a Buffalo nickel that you've got at least one vacuum hose hooked up wrong. There are some good diagrams in that FSM. I bought my truck with a 71 that PO couldn't figure out. He paid a shop to do his head gasket. I found 2 hoses crossedwhen I very carefully checked them against the FSM. Didn't cost anything to fix!

Yes, it was. Replaced both sides, just to be safe, but the right(drivers) side was off, and it is possible there is a vacuum hose hooked up wrong. I'll have to check this out.

Make sure everything is clean. If its just being stupid, jump the connectors with a 10k resister.

Did you ever get the code 71 fixed? If so, how?

I just had the engine light come on again, so I don't think cleaning the EGR is a good long-term solution.

No. It has been running fine, so I wasn't worried about it. Now it's chugging a little when it's cold and there's a little smoke out the exhaust. The smoke doesn't smell like anything other than condensation/exhaust and it's not loosing coolant, so I'm thinking that maybe the smoke is EGR related, rather than the EGR problem being smoke related. There's some interesting wiring splices and stuff hooked up around the EGR, so I think I might check there also.

Also, not sure if it makes a difference, but when I reset the code/disconnect the battery, it takes it usually around 15 minutes to throw the code. I had another code a while back that threw the code immediately after I started the engine.

I've reset mine 3 times now. The first time it took about 5 minutes to throw the code. The second time about an hour of driving (30 minutes to and from work.) Third time was about 15 minutes.

Ok, so it's probably just the way the computer knows that the EGR temp is too low. It might take it awhile to figure it out. Does your's run fine?

Mine usually takes a few hundred miles to come back on. Freaky.

!!!! stop what you are doing and go to Radio Shack !!!! buy the 5 pack of 10k resistors for $.99, trust me. get the fat ones. disconnect the egr temp sensor and use the resistor as a jumper on the female end of the plug. your truck will run better, no CEL and you didn't spend the buck fidy on the egr temp sensor. it works, its cheap and you'll thank me. i jumped mine, replaced the temp sensor with a BOLT w/crush washer and wah-lah. on to the next phase of the never ending toyota fix'em up.

Yes, runs fine. My light came back on on the way to work.

I'd rather not jump the connectors, as I'd like the truck to pass emissions naturally, without any hacks. If it's a bad egr, I'll replace the EGR (even at $125). If it's a bad EGR temp sensor, I'll replace that. I just need to know which of the two it is. I do have a strong exhaust smell when the engine runs, and I'm wondering if the EGR valve itself isn't working as it should.

Should I replace the egr valve (the tower thing off to the side of the head) or should I be cleaning the EGR plate on the back of the head? Is there an easy way to clean the plate on the back of the head? A chemical spray or metal pipe cleaner?

So how do I do that? Do I just hook it up to the positive battery terminal and hook the resistors up and call it good? How many resistors?


Also if anyone else can chime in and tell me if that could damage the engine/egr sensor.

My freaking light came back on at lunch. Just to give you an update I do have an exhaust smell while the engine is warming up but it's pretty much gone once I get to operating temp. I also passed my emissions (did I tell you this?) well enough to get the two year pass. This with the CEL off of course but the same EGR and Temp Sensor in there.

One resistor. I went and got some during lunch and will install one this evening if I get a chance. I'll take a picture or two if I can find the stupid camera. Basically all you do is pull apart the connector in the temp sensor wire and bend the resistor ends (wires) and stick them into the female end of the connection. It makes the ECU think that the temp sensor is reading right where it should be so it doesn't throw a code.

At least that's the way I understand the install and theory behind it.

I get the exhaust smell also. I'll have to check it out later. What size wire? Would speaker wire work for that?

Every car will have an exhaust smell, but I mean mine is bad. I would have no problem replacing the EGR valve right now, but my problem is if it's a bad sensor, that won't fix it. Can I test the sensor? Also, if it's clogged EGR ports on the back of the head, that could affect the EGR valve. So I'm going to clean that all up tonight or this weekend. But I took the EGR valve off a few months ago, cleaned it, and everything was fine for a while. Exhaust still smelled bad, but no CEL.

-edit-
Just a thought, if I ran premium grade gasoline (shell v-power, the stuff with injector cleaner) could that possibly circulate through the EGR system and clean up the place? Since it will be premium, it shouldn't all burn up and shouldn't it recirculate? Or do I have the whole EGR theory wrong?

The resistor has long legs of wire already on it.

Or am I confused by the question?

http://www.ladyada.net/images/conway/staple_t.jpg

thats the right piece. just unplug the sensor and stick that in its place ... done. this is for california models only.


I'M GOING TO WRITE THIS IN ALL CAPS BECAUSE I THINK SOME PEOPLE ARE CONFUSED. IF YOU DO NOT HAVE A CALIFORNIA EMISSIONS ENGINE YOU DO NOT NEED THE RESISTOR. IF YOU DO NOT HAVE A SENSOR THREADED INTO THE TOP OF YOUR EGR, YOU DO NOT NEED THE RESISTOR. THE RESISTOR IS FOR CALIFORNIA MODELS ONLY.