Passed Smog- except EGR?
12-07-11, 01:21 AM
#1
Passed Smog- except EGR?
First off I live in California and am trying to get my RX7 smogged. 1988 T2
I had Mazda put in a reman. engine about 4 years ago, I've only put 12,000 miles on it since then. It still has all the emissions equipment as well as new cats in 2010.
When I got the smog done it passed every element of the inspection (Sniffer, Gas Cap, Cats, Evap, ect...) except for one, in which the guy told me the EGR failed because it didn't effect the idle when he pinched the vacuum line going to it.
My question is, is that a legit reason to fail the car? Would it even pass the other elements of the test if the EGR wasn't circulating? Is there a way for me to check if the EGR is working without having to remove the thing?
I had Mazda put in a reman. engine about 4 years ago, I've only put 12,000 miles on it since then. It still has all the emissions equipment as well as new cats in 2010.
When I got the smog done it passed every element of the inspection (Sniffer, Gas Cap, Cats, Evap, ect...) except for one, in which the guy told me the EGR failed because it didn't effect the idle when he pinched the vacuum line going to it.
My question is, is that a legit reason to fail the car? Would it even pass the other elements of the test if the EGR wasn't circulating? Is there a way for me to check if the EGR is working without having to remove the thing?
12-07-11, 02:08 PM
#2
Go somewhere else for smog testing. There is no test required for the EGR; just a visual inspection. The guy shouldn't be touching much of anything, and I'm not sure that pinching the vacuum line would have any real affect on idle. The EGR also does essentially nothing on a rotary; you can easily pass the NOx requirements of the sniffer portion without one. S5s did not even have an EGR.
12-07-11, 02:50 PM
#3
^ Agreed.
You can test the egr by running 12v across the plug terminals. You can probalby hear it click, but you won't be able to run any air through it. The passage could also be plugged, so even if the valve works, exhaust gases won't pass though. Removing it is only two bolts, but it's a pain to get to. Remove, shoot brake cleaner through the passage and cycle the valve, reinstall.
Or go somewhere else. He can legitimately fail you with a functionality test, but he went out of his way to make you fail.
You can test the egr by running 12v across the plug terminals. You can probalby hear it click, but you won't be able to run any air through it. The passage could also be plugged, so even if the valve works, exhaust gases won't pass though. Removing it is only two bolts, but it's a pain to get to. Remove, shoot brake cleaner through the passage and cycle the valve, reinstall.
Or go somewhere else. He can legitimately fail you with a functionality test, but he went out of his way to make you fail.
12-07-11, 06:12 PM
#5
Sorry, I was unclear. You're testing the EGR solenoid by applying 12v. http://www.cochran-racing.com/FSM/s4...TEMS_TURBO.pdf page 4B-36. Correct EGR test procedure is to apply vacuum not pinch it off. Double check it yourself and you can probably get a free retest if you bring in the sheet.
12-07-11, 10:59 PM
#6
This is the printout from my last smog test. Notice that it reads:
EGR Visual - PASS
EGR Functional - N/A
Unless your county has some other requirements, your test should require the same thing. I've never had anyone try to test the EGR. And if you notice, my NOx was 0.
EGR Visual - PASS
EGR Functional - N/A
Unless your county has some other requirements, your test should require the same thing. I've never had anyone try to test the EGR. And if you notice, my NOx was 0.
Last edited by RotaryRocket88; 12-07-11 at 11:19 PM.
12-08-11, 09:42 AM
#7
^Awesome numbers!!! Here's some extra info about smog checks that most people won't care about.
^From a knowledeable smog tech. There are two test procedures: ASM (on a dyno) and TSI (Two Speed Idle, non-dyno) The EGR test is only applicable to the TSI test. The EGR test is the equivalent of getting a NOx reading from the car while on the dyno. TSI procedure is also needed if your local gas station doesn't want to pay for a AWD dyno just to do smog checks.
In conclusion, he should be taking a NOx reading from the analyzer *OR* testing the EGR. I wouldn't hold it against him since his job is on the line if he lets too many things slide. Hope you get this sorted!
There are 3 portions of a CA smog check that you must pass:
Functional
Meaning all emissions control components must be working as intended. Generally speaking during a smog check, this includes: Checking the check engine light for proper operation, checking the gas cap, checking the EVAP system, checking the EGR system if the test is a TSI.
Visual
Meaning every single emissions control components must be intact and hooked up correctly. Everything from vacuum hoses to EGR Valves. This also includes making sure there are no after market performance parts on your car, and if there are, that they have the appropriate C.A.R.B number with them. With that said, there are no C.A.R.B legal downpipes.
Emissions
Last but not least, you must pass an emissions testing of your tailpipe as laid out here: http://smogcheck.ca.gov/pubwebquery/.../ShowMake.aspx
Functional
Meaning all emissions control components must be working as intended. Generally speaking during a smog check, this includes: Checking the check engine light for proper operation, checking the gas cap, checking the EVAP system, checking the EGR system if the test is a TSI.
Visual
Meaning every single emissions control components must be intact and hooked up correctly. Everything from vacuum hoses to EGR Valves. This also includes making sure there are no after market performance parts on your car, and if there are, that they have the appropriate C.A.R.B number with them. With that said, there are no C.A.R.B legal downpipes.
Emissions
Last but not least, you must pass an emissions testing of your tailpipe as laid out here: http://smogcheck.ca.gov/pubwebquery/.../ShowMake.aspx
In conclusion, he should be taking a NOx reading from the analyzer *OR* testing the EGR. I wouldn't hold it against him since his job is on the line if he lets too many things slide. Hope you get this sorted!
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12-20-11, 01:20 AM
#8
Sorry for the slight revival here, I just was able to find and compare my Emissions sheet to the one posted up there, along with the info RXSpeed16 posted I see now that I was doing the TSI test, which must be why I failed? I suppose, though my EGR functions as it should when I follow the test in the FSM. Not sure how to go about getting my car smogged now, as I live pretty far in the woods of Norcal now, and the service station I went to is the only one in about 100 miles of this place.
Might have to do the 50$ bill coax :X
12-20-11, 05:20 PM
#9
Yeah, that's why you failed. NOx wasn't measured, which is what the EGR is there to reduce. Test the EGR yourself per the FSM, and if it works out, print the pages and go back to this place demanding a free re-test.
Or check your county's smog test requirements, and find a place that does the ASM test.
Or check your county's smog test requirements, and find a place that does the ASM test.
12-21-11, 01:57 PM
#10
To correctly test the EGR on an S4 during a TSI, the technician has to apply vacuum to the EGR valve during idle. If functioning correctly, the idle will drop and possibly shut the engine off.
You have a couple options here:
1a. You can check the EGR yourself at home with a vacuum pump and if it is working correctly take it in and get a retest. Be cool with the guy, tell him you checked it yourself and it seems to be operating correctly and ask if he can just check it real quick before he does the retest.
1b. You can check the EGR yourself at home with a vacuum pump and if it is found to not be working correctly you can at that point repair it. This would involve taking the EGR off and replacing it if needed, and/or cleaning out the passage ways.
1c. If you are too lazy to fix the EGR (if it is infact not functioning), you can try to take it to another shop and hope that they are too lazy to check the EGR.
2. Register your car in an enhanced smog check area. Here is a map of the smog check program areas.. This will force your car to require an ASM test in which the car isn't subjected to an EGR functional check. HOWEVER, if your EGR is not working, it may be reflected in a high NoX reading and possibly cause you to fail the test.
You may read (I know I have) posts about how a Rotary doesn't need an EGR and you should be fine on NoX even if it isn't working. However, these posts are clearly unfounded and obviously aren't coming from a 6+ year smog technician. I will tell you right now, S4s DO fail on NoX, and it is more often than not caused by a faulty EGR. IF S4s were designed from the get go to not have an EGR like an S5, it would be different; but they weren't.
Good luck!
You have a couple options here:
1a. You can check the EGR yourself at home with a vacuum pump and if it is working correctly take it in and get a retest. Be cool with the guy, tell him you checked it yourself and it seems to be operating correctly and ask if he can just check it real quick before he does the retest.
1b. You can check the EGR yourself at home with a vacuum pump and if it is found to not be working correctly you can at that point repair it. This would involve taking the EGR off and replacing it if needed, and/or cleaning out the passage ways.
1c. If you are too lazy to fix the EGR (if it is infact not functioning), you can try to take it to another shop and hope that they are too lazy to check the EGR.
2. Register your car in an enhanced smog check area. Here is a map of the smog check program areas.. This will force your car to require an ASM test in which the car isn't subjected to an EGR functional check. HOWEVER, if your EGR is not working, it may be reflected in a high NoX reading and possibly cause you to fail the test.
You may read (I know I have) posts about how a Rotary doesn't need an EGR and you should be fine on NoX even if it isn't working. However, these posts are clearly unfounded and obviously aren't coming from a 6+ year smog technician. I will tell you right now, S4s DO fail on NoX, and it is more often than not caused by a faulty EGR. IF S4s were designed from the get go to not have an EGR like an S5, it would be different; but they weren't.
Good luck!
12-22-11, 01:30 AM
#11
You may read (I know I have) posts about how a Rotary doesn't need an EGR and you should be fine on NoX even if it isn't working. However, these posts are clearly unfounded and obviously aren't coming from a 6+ year smog technician. I will tell you right now, S4s DO fail on NoX, and it is more often than not caused by a faulty EGR. IF S4s were designed from the get go to not have an EGR like an S5, it would be different; but they weren't.
12-23-11, 11:52 AM
#12
FYI: I've smogged over 15,000 cars in a period of 6 years while the entire time working right next door to a Rotary specialist; literally hundreds of FCs from either the Rotary shop OR forum members have been smogged by me personally.
There are so many circumstances to change a cars emissions; and yes, a good running rotary with a good cat and working air pump typically has low NoX no question. HOWEVER, I have personally seen MULTIPLE times elevated levels of NoX cause an S4 to fail. I have also seen a small handful of S5s fail on NoX.
As a matter of fact, a poster IN THIS VERY THREAD (RXSpeed16) was failing on NoX in his S4 TII at my smog shop.
Again, there are plenty of factors to change a cars emissions, such as old tired engine, operation of air pump, old worn out cat, fuel mixture, carbon build up, and many more. The problem here is you are using your own personal car, which judging by your online persona is/was probably well taken care of, as a basis to call me out on a personal observation that stems from 6+ years of experience.
Oh, and if you look at the middle column of each emissions reading, you'll notice that it says "AVE". This is the average reading for your year/type of vehicle. This is known to be fudged lower, so the BAR can encourage stations to do better repairs for a failed vehicle. Notice the "AVE" for NoX is 153/143? That tells you that the average NoX for 88 Rx7s is AT LEAST 153/143; if it was 0, then "AVE" would say 0. Thus, your car is not a good example at all of an 88 Rx7s typical emissions. This is even more apparent when you look at your CO and HC readings which are waaaay lower than average. If I had to guess, I would say you have brand new cat on that car.
Anyways, I for one enjoy reading your posts and contributions, as you are very wise in the ways of FCs. Heck, sometimes I will be skimming over threads and if it says you were the last poster I usually read the thread cuz more often than not I learn a little something. So thanks for your contributions!
There are so many circumstances to change a cars emissions; and yes, a good running rotary with a good cat and working air pump typically has low NoX no question. HOWEVER, I have personally seen MULTIPLE times elevated levels of NoX cause an S4 to fail. I have also seen a small handful of S5s fail on NoX.
As a matter of fact, a poster IN THIS VERY THREAD (RXSpeed16) was failing on NoX in his S4 TII at my smog shop.
Again, there are plenty of factors to change a cars emissions, such as old tired engine, operation of air pump, old worn out cat, fuel mixture, carbon build up, and many more. The problem here is you are using your own personal car, which judging by your online persona is/was probably well taken care of, as a basis to call me out on a personal observation that stems from 6+ years of experience.
Oh, and if you look at the middle column of each emissions reading, you'll notice that it says "AVE". This is the average reading for your year/type of vehicle. This is known to be fudged lower, so the BAR can encourage stations to do better repairs for a failed vehicle. Notice the "AVE" for NoX is 153/143? That tells you that the average NoX for 88 Rx7s is AT LEAST 153/143; if it was 0, then "AVE" would say 0. Thus, your car is not a good example at all of an 88 Rx7s typical emissions. This is even more apparent when you look at your CO and HC readings which are waaaay lower than average. If I had to guess, I would say you have brand new cat on that car.
Anyways, I for one enjoy reading your posts and contributions, as you are very wise in the ways of FCs. Heck, sometimes I will be skimming over threads and if it says you were the last poster I usually read the thread cuz more often than not I learn a little something. So thanks for your contributions!
12-23-11, 07:33 PM
#13
First off, just let me say I'm not trying to be a dick about it, and I probably could have worded my reply a little nicer. But I don't agree with your comment about the EGR valve at all. Neither S4s nor S5s need the EGR, and the S5 ECU is not "tuned" to not use an EGR. The 02 sensor feedback system and secondary air injection system are almost identical. The rest of what you've said is correct.
It's not that a rotary could not fail for NOx. I said that an EGR was basically useless on a rotary, and was not needed to pass a smog test. A working catalytic converter, secondary air injection system and O2 sensor are FAR more important. As long as they're working properly, you don't need an EGR.
1) If the cat is ancient, or there is not enough air being directed to it, you'll end up with poor scavenging of CO, HC & NOx.
2) If the cat only contains a 2-way catalyst, there will only be two reactions:
CO + O2 -> CO2
HC + O2 -> CO2 + H2O
There will be no scavenging of NOx, so what little there is may still be enough to fail the sniffer test.
3) If the airpump is wasted or the ACV solenoids are disabled/broken, too little 02 will be present to convert HC, CO, NOx. Levels at the tail pipe will go up.
My own car is a perfect example of what the emissions should be if the emissions equipment is working as it should (minus an EGR). My cat is also not new at all; it's an old used cat that just happens to work very well.
This is a page out of the '86 training manual:
In figure 1, it can be seen that NOx production sharply decreases when the air/fuel mixture is less than 14.7:1 (stoichiometric ratio).
From figure 2, we can see that the conversion of NOx in a 3-way cat also greatly benefits from a richer mixture. Under rich conditions, the reaction highly favors the production of O2 and N2. If the mixture moves to the lean side, the starting material (NOx) tends to be favored.
Figure 3 shows NOx at the tailpipe to be almost 0 if the mixture is less than 14.7:1, but it skyrockets if the mixture goes lean.
Any of the stock FC ECUs will generally run the engine pretty rich. Hell, an NA ECU will run 10-11 AFR under full load at high RPMs. During cruising, the ECU will attempt to use O2 sensor feedback to keep the mixture at 14.7:1, but it's not very good at it. The narrowband sensor is extremely crude. The mixture will bounce back and forth, but generally stay a little more on the rich side. Rich mixture = Low or no NOx.
Now, I know the TSI test doesn't measure NOx, but the EGR also does not function at idle. It only operates between 1700 and 3600 RPM & while the engine is in vacuum. The 02 sensor input is also not used at idle, and a rotary likes to idle at about 12-13 AFR. Rich mixture = Low or no NOx.
A rotary is also not exactly that fuel efficient and exhaust gas temps are higher than that of a piston engine. Both of these contribute to better catalytic converter function and favorable conversion of NOx.
It's not that a rotary could not fail for NOx. I said that an EGR was basically useless on a rotary, and was not needed to pass a smog test. A working catalytic converter, secondary air injection system and O2 sensor are FAR more important. As long as they're working properly, you don't need an EGR.
1) If the cat is ancient, or there is not enough air being directed to it, you'll end up with poor scavenging of CO, HC & NOx.
2) If the cat only contains a 2-way catalyst, there will only be two reactions:
CO + O2 -> CO2
HC + O2 -> CO2 + H2O
There will be no scavenging of NOx, so what little there is may still be enough to fail the sniffer test.
3) If the airpump is wasted or the ACV solenoids are disabled/broken, too little 02 will be present to convert HC, CO, NOx. Levels at the tail pipe will go up.
My own car is a perfect example of what the emissions should be if the emissions equipment is working as it should (minus an EGR). My cat is also not new at all; it's an old used cat that just happens to work very well.
This is a page out of the '86 training manual:
In figure 1, it can be seen that NOx production sharply decreases when the air/fuel mixture is less than 14.7:1 (stoichiometric ratio).
From figure 2, we can see that the conversion of NOx in a 3-way cat also greatly benefits from a richer mixture. Under rich conditions, the reaction highly favors the production of O2 and N2. If the mixture moves to the lean side, the starting material (NOx) tends to be favored.
Figure 3 shows NOx at the tailpipe to be almost 0 if the mixture is less than 14.7:1, but it skyrockets if the mixture goes lean.
Any of the stock FC ECUs will generally run the engine pretty rich. Hell, an NA ECU will run 10-11 AFR under full load at high RPMs. During cruising, the ECU will attempt to use O2 sensor feedback to keep the mixture at 14.7:1, but it's not very good at it. The narrowband sensor is extremely crude. The mixture will bounce back and forth, but generally stay a little more on the rich side. Rich mixture = Low or no NOx.
Now, I know the TSI test doesn't measure NOx, but the EGR also does not function at idle. It only operates between 1700 and 3600 RPM & while the engine is in vacuum. The 02 sensor input is also not used at idle, and a rotary likes to idle at about 12-13 AFR. Rich mixture = Low or no NOx.
A rotary is also not exactly that fuel efficient and exhaust gas temps are higher than that of a piston engine. Both of these contribute to better catalytic converter function and favorable conversion of NOx.
Last edited by RotaryRocket88; 12-23-11 at 07:39 PM.
12-24-11, 12:52 AM
#14
As a matter of fact, a poster IN THIS VERY THREAD (RXSpeed16) was failing on NoX in his S4 TII at my smog shop.
Again, there are plenty of factors to change a cars emissions, such as old tired engine, operation of air pump, old worn out cat, fuel mixture, carbon build up, and many more. The problem here is you are using your own personal car, which judging by your online persona is/was probably well taken care of, as a basis to call me out on a personal observation that stems from 6+ years of experience.
Again, there are plenty of factors to change a cars emissions, such as old tired engine, operation of air pump, old worn out cat, fuel mixture, carbon build up, and many more. The problem here is you are using your own personal car, which judging by your online persona is/was probably well taken care of, as a basis to call me out on a personal observation that stems from 6+ years of experience.
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