Buck01

Hi Guy's I have been lurking around for a week or so and done lot's of searchs and found some great info. Thanks

My question is this. I get the above error code. I looked it up in my Haynes manual. It says it is EGR related. I checked all the vacum hoses. they look fine. I have even replace the EGR valve. (not exactly cheap). The problem is I still get the same error. Although now it seems to come and go , where before the CEL stayed on.

The manual says something about it it possible being a "low exhaust gas temp". It does not tell you where the temp sensor is though.

I (think) it is in the EGR valve assy at the back of the intake?? Does that sound right? If not where is it? and is there a way to test it?

Or any other suggestions you might have?

Here are some of my specifics...94 toyota truck 22RE engine with 5spd trans the truck has 175,000 miles on it.
I have added a high performance head with bigger cam and valves a 4 months ago. I just put on a complete LC Engineering header and cat and high flow muffler kit. I also just replaced the plug wires they were shot.

Thanks in advance for any help

Joel

Buck01

Gonna bump this up. Someone has to have a suggestion???

Buck01

has no one had to deal with error code 71 or is it different on a 4 runner?

jx7

I have an intermittent check engine light that turned out to be the same code. In the Haynes manual I have, it says it's a California only code. As far as I know, my 4Runner was never a CA vehicle, so that seems a bit odd to me. But it looks like the EGR modulator needs replacing, so I'm hoping that turns out to be the only issue.

Buck01

I replaced my EGR valve and it didn't help. It's kinda price at 159.00 dollars.

let me know what you find out.

Thanks

Joel

mtnfreak

I've had the same problem for years - just pops up once in awhile. The EGR gas temp sensor screws into the side of the EGR valve - look closely and you'll see a threaded hole on the outside of the valve. Only California vehicles had this until recently, so the problem must be somewhere else. If you haven't replaced the O2 sensor in 100K miles or so, I'd start there. If you don't have one due to your exhaust work, then that may be the problem - any correlation between the code and the work?

Buck01

I have a temp sensor on the EGR.
I have a O2 sensor. not sure when it was last replaced. only had the truck for a year.

the light did start after the exhaust work.

punkbek3886

i think the sensor is mounted between the intake manifold and the valve. it senses the temperature of the exhaust gas traveling through the pipe into the intake. the computer knows when the valve should be open or closed and if the temperature sensor doesnt send a corresponding signal the light goes on. it could mean that its always flowing exhaust or that it never opens. the problem could be anything in the egr system. i dont know why the haynes manual says its for california vehicles only, it seems to be the most common ecm code with these engines, and i know my vehicle has a temp sensor and it didnt come from cali.

NathanBERG

I Just got the code 71
I took off the Vac line form the modulator leaving it conected to the EGR valve and sucked, nothing happend? Dose this mean the EGR valve is shot?

MTL_4runner

More than likely, yes, but be sure you don't have a bad vacuum hose either.
You can try using a hand actuated vacuum pump (like you use for bleeding brakes).
The diaphragm should move with vacuum applied.

Snorkeldepth

I have a 3.0 and I'm in the middle of code 71 trauma. I replaced the valve (including the pipe when the valve body broke off inside the flare nut) and the modulator. I had a 71 code in the past that was solved by a new modulator. You can open up your modulator and check the filter to see if it looks dirty. Sometimes you can just spin the filter 180 degrees and it will help. My next step is to replace the temp sensor. Apparently the EGR vsv can be a source of the code as well.

Hopefully we'll both emerge victorious from this.

NathanBERG

Great help guys! I will look into all that stuff before replacing the EGR valve.

Thanks!