treehan77
TYF Fiend
Sounds like you were lucky!
Smog check fail and ac quit !
- Thread starter Steve Waddington
- Start date
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OP
OP
Steve Waddington
Senior Member
Fingers crossed!
Hoping for the best. I was down that road for a long time, finally after replacing all 3 it was resolved.
OP
OP
Steve Waddington
Senior Member
Anyone know what a true “drive cycle” is? Now that I have these things replaced, I want to get my ‘hoe smog checked and registered. Problem is, with us on lockdown, and my industry eliminated for the foreseeable future, I really don’t have anywhere to go!
OP
OP
Steve Waddington
Senior Member
And, as long as I was there, I gave the engine bay a bit of a bath...
OP
OP
Steve Waddington
Senior Member
I don’t think the previous owner ever cleaned the motor. Until today, I actually thought the valve covers were black.
The OBDII drive cycle begins with a cold start (coolant temperature below 122 degrees F and the coolant and air temperature sensors within 11 degrees of one another). NOTE: The ignition key must not be on prior to the cold start otherwise the heated oxygen sensor diagnostic may not run. 1. As soon as the engine starts, idle the engine in drive for two and a half minutes with the A/C and rear defrost on. OBDII checks oxygen sensor heater circuits, air pump and EVAP purge. 2. Turn the A/C and rear defrost off, and accelerate to 55 mph at half throttle. OBDII checks for ignition misfire, fuel trim and canister purge. 3. Hold at a steady state speed of 55 mph for three minutes. OBDII monitors EGR, air pump, O2 sensors and canister purge. 4. Decelerate (coast down) to 20 mph without braking or depressing the clutch. OBDII checks EGR and purge functions. 5. Accelerate back to 55 to 60 mph at æ throttle. OBDII checks misfire, fuel trim and purge again. 6. Hold at a steady speed of 55 to 60 mph for five minutes. OBDII monitors catalytic converter efficiency, misfire, EGR, fuel trim, oxygen sensors and purge functions. 7. Decelerate (coast down) to a stop without braking. OBDII makes a final check of EGR and canister purge.
Enough miles of driving will put the vehicle in each of the required conditions, but doing it systematically may save time. More than one repetition of the cycle may be needed.
And I don’t know how or where a person is supposed to go from 55 to 20 by coasting without people thinking your cray cray on the highway and you might get rear ended. I always thought that part of it was ridiculous.
Seriously, no way that would fly around here....
It’s easy here in Iowa. Find a country road on a Sunday and slow down like all the farmers who are out looking at everyone else’s corn fields and doing 20 mph so they can get a good look.
Oh there’s places here to do that too, out in the country. My issue is that, at least from my understanding, is this needs to be done within a short time of doing the rest of the drive cycle. The instructions say to let it idle after a cold start 2 1/2 minutes with the AC and rear defrost on, then immediately accelerate to 55, then coast to 20, etc. I did try completing a drive cycle on my 08 Silverado several times but never succeeded. I couldn’t get one of the sensors to complete, I don’t remember which one. I figured I’d have to go sleep in the truck out in the countryside. So instead I registered it in a county that doesn’t require a smog check.
That fuggin evap takes forever....
George B
¯\_(ツ)_/¯
Makes it worth having a scan tool that can command the test.
I have a Tech2. The Evap states “not ready” if the drive cycle is incomplete. There’s nothing you can do. It won’t test if it’s not ready. Ugh.
Ya doing the evap test with the tech2 is a chore, temp has to be right, you have to time the ignition and buttons just right, then you have to hold the rpm's just right. and if you screw up you have to start all over.
for someone like me I need a external throttle control like you used to be able to use with your hand
the smog tech here in california told me just go drive it 50 miles at 55mph which worked but you dam near get ran off the road because nobody drives 55 here not even the semi's even though there supposed to
for someone like me I need a external throttle control like you used to be able to use with your hand
the smog tech here in california told me just go drive it 50 miles at 55mph which worked but you dam near get ran off the road because nobody drives 55 here not even the semi's even though there supposed to
George B
¯\_(ツ)_/¯
I stand corrected. Good to know.
Scottydoggs
Full Access Member
i own a hptuners, once in my old car i failed cause stuff was not ready yet. so i drove the mile home, deleted all the codes and passed with flying colors. got home and undeleted them.
Tonyrodz
Resident Resident
Strange that it worked Scotty. I used to do inspections at Eatontown and people would clear their codes before coming. They'd always fail because the sensors weren't ready yet.
Yeah that’s not right @Scottydoggs there’s no way to pass emissions after deleting any emissions related DTC’s without a drive cycle, and all the sensors have to report as “ready” with no codes present, which takes a drive cycle or several. It’s set up like that expressly so people can’t just clear codes and then drive through emissions testing.
Scottydoggs
Full Access Member
you would be dead wrong there. my regal had 25 codes deleted, egr, evap cat, rear o2. the only thing left was the up stream o2. that you want to know is going bad via the code. once deleted and set to no report all them tests for those items are set to ready as soon as you flash it. NO DRIVE CYCLE NEEDED.
my thaoe has a rear o2 deleted cause it went bad and it passed inspection just like the regal did for 10 years.
this is fully check able with a scanner that shows "im readyness"
the tune in my camaro also has a ton of codes deleted, evap is one of em.
now theres perma codes in newer cars and trucks 16 or 17 up, that cant be deleted if they set the light. they need to pass their tests so the perma code goes away, then delete it to kill it.
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