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Who really understands codes and emission testing?

Mastiff

Mastiff

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I'm in AZ where emission testing is required. For newer vehicles, they just plug in to the OBD2 port for the test, no actual emissions or rollers or anything. I know I will certainly fail if I have a check engine light, but I will also fail if I bring my reader and clear the code 5 minutes before the test, right?

I have an annoying EGR related code that I cleared, then it came back like two weeks later. I wonder, could I have passed the test the day before the code came back? How does this work, and is there any way to know up front if I will pass?

This is for my Jeep, and the EGR is a nightmare to access. I have no drivability issues, so I don't care to fix it if I can pass my test.
 
in new york the test is the same plug in and read for codes and monitors not run / incomplete / also for turned off functions like custom tunes turning off rear o2 sensors .

you will prob be the same basic test setup .

clear the codes / drive it and test for monitors incomplete or not run yet . find out how many your allowed to have not run to pass . then get it in and tested before your egr code pops back up .

cheep code readers can show the code # only and how many codes are in it or pending to set a light . also it will show monitors run / incomplete . i have a cheep reader for 25.00 bucks that does just this and lets you clear codes also .

cp9125.jpg


here in ny last i recall its 96-00 = 2 not run / incomplete - 01-to like 06 or so = 1 not run / incomplete / and newer i dont think you can have any not run .

also here if over 8,600lb gvw registered or diesel = no plug in test . . . . yet . . . just safety .
 
Okay. My reader is decent, cost me $100 or something. I'll poke around and see if I can find an indication of unrun tests. It's would be weird to me if the EGR test only ran every two weeks.

It just occurred to me that I did modify the computer to ignore TPS, which I got rid of. Hopefully that won't be a problem.
 
most will call it monitors on a lot of the scanners . or state obd test or along those lines .

tps = tire pressure sensor ? i have not heard of that failing them . there looking for the emissions / trans side of the codes mostly
 
Sorry, it's TPMS, tire pressure monitoring system. Yeah, they shouldn't care, but who knows withe the government. The whole thing is a waste of time and resources at this point, as far as I'm concerned. Cars don't go out of tune and belch pollution anymore.
 
Two weeks should be plenty of time to for the ECU to clear the code assuming you drive it daily. It’s all about the heat cycles and miles that clears the codes from the memory.
 
codes self clear after 40 key on/off runs IF the problem dont show back up .

and just cause the light is off dont mean its out of the stored system memory . ALWAYS check it your self .
 
sweetk30 said:
n new york the test is the same plug in and read for codes and monitors not run / incomplete / also for turned off functions like custom tunes turning off rear o2 sensors .
Click to expand...

MONITOR is the key word here. Even if a fault code is not currently set in the ECM the Arizona states interface OBDII scanners will pick up a thing called a "monitor". Meaning the OBDII/ECM is "monitoring" a situation that is occurring in your vehicle. IIRC.
 
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sweetk30 said:
codes self clear after 40 key on/off runs IF the problem dont show back up .
Click to expand...

Is that a Jeep specific note? Every manufacturer has a different process for clearing codes. I’ve never heard of any vehicle that only requires 40 on off clicks.
 
seems to be the general average i have always heard . i my self do NOT go by it tho . i use a scanner and check it my self first hand .
 
Yes the newer obdII testing are checking for codes, and that monitor test have completed and passed. The monitor test are self test of various systems, misfire, evap controls, o2 sensors, egr and others.
When you clear codes you also clear the monitor status to not run. Then thru normal driving, or a set test drive routine, each monitor test will run under the driving conditions to best complete the test.
Some states will let cars pass with 1 or 2 monitor test incomplete. But I think there are certain monitors that they require be run and passed.
If you don't cruise high speed you may not get the egr malfunction, but the monitor may not run as well
 
I've got the obdlink bluetooth. Works w/ torque app and both obdlink and torque will have a 'readiness' section that will show if the drive cycles have completed. Sometimes it can take weeks of driving to hit the completion point on all of the applicable tests.

Screenshot_20181019-083238.jpg
 
JoshHefnerX said:
I've got the obdlink bluetooth. Works w/ torque app and both obdlink and torque will have a 'readiness' section that will show if the drive cycles have completed. Sometimes it can take weeks of driving to hit the completion point on all of the applicable tests.

View attachment 320361
Click to expand...
That's what I use
 
Yes an ELM327 obdII code reader and Android phone work fairly well. I have OBD Auto Dr, which was great till it changed to annual subscription for Pro ver. Torque Pro good for tuners. Leaf spy Pro, is picky about the version of Elm chip, I know it works with v1.5. I have tried others but they didn't make the cut.
Oh and I have an older version of OBD Auto Dr, I am not going to update. To avoid annual subscription
 
I see three versions of OBDlink on Amazon. Which one do you guys like?
 
Mastiff said:
I'm in AZ where emission testing is required. For newer vehicles, they just plug in to the OBD2 port for the test, no actual emissions or rollers or anything. I know I will certainly fail if I have a check engine light, but I will also fail if I bring my reader and clear the code 5 minutes before the test, right?

I have an annoying EGR related code that I cleared, then it came back like two weeks later. I wonder, could I have passed the test the day before the code came back? How does this work, and is there any way to know up front if I will pass?

This is for my Jeep, and the EGR is a nightmare to access. I have no drivability issues, so I don't care to fix it if I can pass my test.
Click to expand...


Hey there....Im also here in the PHX valley, and for what its worth, I have had the same problem with my 2001 Sport Trac EGR.

Problem was the little vacuum line that supplies the signal to the EGR (attaches directly to the EGR valve via a rubber boot) would come loose and pop off due to the little 90 degree rubber boot that it pushes into drying out and cracking. Replaced the boot with an aftermarket one from oreillys, plugged the line back into it, cleared the code with my Autell reader and drove the car around a bit to let the ecu moniters do their monitoring. I stopped once and turned the car off, let it cool a bit, restarted and did a loop down the 101 to I17 and home again (maybe 10-15 miles), parked, shut it down and checked it with the reader again.....the moniter test showed it was ready for testing at that point so I drove over to the testing station and got it done.

Ive had this happen twice now and like you the car runs fine and no different with the line detached. I don't know exactly what is takes to reset but there is an algorithm that requires a certain number of miles and starts before the moniters are 'reset'. Your results may vary. And yes, testing is a PITA and worse if you dont have ODBII. The reader has payed for itself already. Hope this helps.
 
Weird thing is that now that I know what I'm looking for, I looked on the reader and the EGR test has run and passed. So it must be some intermittent thing. The O2 test has not run, and surfing around I see that some people have had real trouble getting the O2 test to run. Looking on the AZ emissions web site, they allow one test to be not run and you can still pass. So, if you have a reader and clear the codes, I guess you can have one faulty system and still get by as long as you go to the station before it runs and fails.
 
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