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No input on the EGR module? Can anyone with a module handy try testing it and see if port R and P have equal air resistance or that it matches my results?

 

Still battling with this one, CEL has not thrown the code 71 since that one time and I've reset the codes and driven it a bunch. I've tested the EGR using the below method. It says I should get a 100-300 rpm increase and I get no increase. I am assuming the EGR is not functioning but each component is testing out ok which is driving me nuts. It's like it's just not getting vacuum to trigger the EGR valve but nothing is showing me I have a vacuum leak or other vacuum issue. I've gone through each step of the link posted above and still no luck.

Today I pulled the throttle body and cleaned the vacuum passages, I haven't retested to see if that helped but they weren't clogged. Also decided to just replace the vacuum modulator because it was cheap enough to throw at it.


INSPECT SYSTEM OPERATION
(a) Using SST, connect terminals TE1 and E1 of the check
(”DIAGNOSIS”) connector.
SST 09843–18020
(b) Keep the engine at 3,500 rpm.
(c) Set the transmission shift lever to the ”N” position.
(d) Remove the SST from the check connector.
SST 09843–18020
(e) Check whether the engine rpm increases 100–300 rpm
under the following conditions:
Coolant temp.
Below 53°C (127°F) No increase
Above 55°C (131°F) Increases

 

i had to check your profile to see you are talking about an sc300.
how high are your nox readings? you should really post all the values.
If you cleaned the tube, it stumbles when you yank the diaphram, and you replaced the vacuum modulator it may be time to look elsewhere.

make sure you are using premium gas, cheap gas can hurt your nox. it could help to verify your base timing especially if the ecu isnt jumping up in rpms after you remove the pins from the terminals. some people like to turn the dizzy a little advanced.. good for power not for emissions.
make sure you warm those new cats up before you take it in, give it a few pulls to allow the extra unburned fuel to heat up the catalysts. the coolant temp needle sitting in the middle is not an indication that your cats are warmed up. take a long way to the station, try and hit the highway. you can even use some octane booster if your other numbers are well within spec.

Also have you changed your o2 sensors, if you are running more on the lean side due to a tired sensor, it will also give you high nox even if your cats are good. alot of poeple unnecessarily replace cats they think are bad to find out the problem was elsewhere.
those are all the things i can think of off the top of my head, good luck.

oh yeah, also code 71 doesnt automatically mean your egr system isnt working, it can also be set off when the egr probe reads a value that is too high, usually from a lean mixture causing high combustion temps (or an actual clogged egr pipe). For example my egr valve worked perfectly, passed emissions, never threw a code. 1 week after throwing on the turbo and doing some pulls, I would almost always set off the egr code, basically due to the higher exhaust temps. So basically while the egr system can be working just fine, if it cannot regulate the probe temp to stock specs it will throw the code.
often times the higher combustion temps are unrelated to the egr system entirely, something else gets to a point where the egr can no longer compensate. I hope that made sense.

 

Ah, I feel dumb. I posted on several forums and some how forgot to post all the crucial details on this one... Maybe better to just start over.

All test were done after flogging the car on the freeway pretty heavy with the O/D off for at least 30 minutes and then going right onto the dyno. Test 3 however was actually rainy and slightly cooler outside. I've been told that may have thrown my results but by that large of a number I'm not sure(plus the other issue).

Ok, The 95 sc300 (2jzge) failed really bad the first time around.
Test 1: Results / Allowed
HC .94 / .80
CO 2.37 / 12.00
NOX 4.43 / 2.00

I had 2 new magnaflow cats welded in and re-test.
Test 2:
HC .20 / .80
CO 3.23 / 12.00
NOX 2.21 / 2.00 (ahhhh .2!)

Checked the timing and it was advanced(by PO), set timing to stock as recommended by the internet for re-test.
Test 3:
HC .32 / .80
CO .70 / 12.00
NOX 8.21 /2.00 (aaahhhh!!!)
Graph they gave me for test 3.

Since test 3 I have pulled the EGR valve and cleaned it very thoroughly. Cleaned the throttle body with extra attention on the vacuum passages also the Y pipe. Cleaned the EGR temp sensor, it was really fouled up but now fully clean. Timing has been set at 10* and re-checked several times.

I've tested the EGR with the car running, apply vacuum to the EGR directly and the idle drops and the motor wants to stall as more vacuum is applied. Tested the EGR temp sensor resistance at the suggested temperatures and it passed. Tested then later replaced the EGR vacuum module so it's new from the dealer. Checked for vacuum leaks with my vacuum gauge and using carb cleaner, no leaks found. Checked resistance on the EGR vacuum VSV and it checks out. Tested for proper vacuum operation of the VSV and it passes.

After all the cleaning and testing, I rest the ECU and drove it. The next day code 71 showed up. I cleared the codes and drove it for over a week now and the code has not showed back up. I have a smooth solid idle running 91 octane from the same station/pump that I use with all 4 of my vehicles. There is also no fuel additive of any kind in the tank.

The only test from the FSM I am failing is the one posted above. With the car at operating temp and pulling the jumper pin with the RPM at 3,500 I am seeing Zero change in the RPM when I should see 100-300 RPM increase. It is as if all the components of the EGR function but the car is not controlling the EGR. I'm not sure what else to test however.

I have been thinking the o2 sensors but was hesitant to just replace them as they are not throwing a code. Also since I got the code 71 that one time I was figuring the problem was in the EGR system and since I am failing the EGR system test.

The emissions place printed the graph for me and they seemed really hopeful that the graph when shown to the right people would make it easy to diagnose.

 

well you have done a pretty thorough job so far. Im no expert but i have tripped code 71 on a very consistent basis with the stock ecu and it had nothing to do with my egr.
If code 71 showed up on an n/a with a working egr (lets assume it works) that means your combustion temps are really really high. since you are saying 91 im guessing you live at an elevation and thats the best gas you can get, so that shouldn't be the issue.
timing you said you checked, im gonna guess you checked your plugs/cap/rotor. The only major thing left is fuel, and a prolonged lean condition could be the cause of that. People with turbo 2jz's with no egr can pass smog with a good tune and a cat. If you have a lot of miles and have never changed the o2 sensors i would start there, and the funny thing is bad o2 sensors on odb1 toyotas rarely throw the code. they will cause you years of driveability and emissions woes before that little light ever comes on when it completely fails. the 2jz can run very lean at idle with a good amount of advance and not show much driveability issues. I would start with the o2's and also test the Maf which can cause the same lean problem. If you have an air leak in the intake system that can also cause a lean condition, particularly the crank case vent hose where it goes to the intake, make sure that piece is intact, along with the pcv side hose.

 

Did they only give you the 3 gas values?

Punching them in the Lambda calculator you are at .3 lambda which is around 4.86 air fuel ratio which is way to rich.

I would suspect that your O2 sensors are bad so check them out may need replacing.

Look at your spark plugs for proper color.

Is your oil black and smell like fuel? If so you will want to change it also before the test.

You can usually go within 3 degrees of spec on the timing. Retarding will usually lower NOx

Are you also getting bad fuel mileage?

 

Thanks for the input guys.

Those are all the numbers they gave me and the graph printed out.

91 octane is the highest I can get here yes, the cap, rotor, plugs, wires and air filter were all changed a few months ago(all oem lexus). Oil was changed recently and was fine no fuel smell or anything out of the ordinary. I'm not sure on fuel mileage, it's the ole ladies car and she doesn't track the mileage per tank like I asked....

If you guys are all thinking o2 sensors I may just replace them as routine maintenance and hope it solves all the issues. I was actually going to go for my free re-test today having been through all the EGR system. However, after reading this info I may hold off so I won't have to pay for my next set of tests, $30 for 2 tests is adding up fast.

 

Should help some.
http://www.heartland.org/policybot/r...ions_Test.html

 

Well, you guys were right. I replaced the 2 o2 sensors with OE ones from rockauto for 88 bucks and took it for my test. I passed with flying colors, my NoX was down to 0.2.

Thanks for the input I would have stayed focused on the EGR system because of that code 71.