Please help before I drive thing into the lake

[Majindan]

2002 SR5 4WD, 158k miles, CA emissions B.S. P0420 code about a month ago, replaced downstream 02 with a proper Denso sensor, up stream sensor is Denso and under 10k miles old, front cat was installed same mileage ago. Check engine light has NOT come back in two weeks since I put the downstream sensor in. Have a compatible bluetooth OBDII and Torque Pro, using real time data to monitor. Now, the catalyst and evap tests show complete one day, then incomplete the next, and then one is complete, then the other is not and vice versa. I've read the PDFs from Toyota stating how to complete said tests, and just finished trying to get them completed following the guide. Checked all fuses, no CEL at all, just the tests keep jumping from complete to incomplete.

WTF is going on with this thing? I've never had so much trouble with something like this and I'm about at my wits end. What would cause the ECU to show complete then just, I dunno, change it's mind and do it over for this long?

I have to run this thing through emissions (I'm in TN) within two weeks and it won't pass bc of this crap. MPGs are around 18-20, idle is perfect, doesn't cut out under acceleration, I put a brand new OEM gas cap on a few weeks ago, cleaned the MAF thoroughly, replaced and checked all vacuum lines.

Is there a way to test the ECU for errors or would it just throw a CEL if it wasn't passing it's own diagnostics?

 

[Nate_GB]

So the truck is, or is not still throwing emissions codes? Please specify which "tests" you are referring to?

The truck will complete on board tests of the emissions equipment periodically with certain requirements such as:
gas tanks between 25% and 75% full
truck at operating temp
longer than 15 minute run time
etc.

Are these the "tests" you're referring to?

 

[Majindan]

So the truck is, or is not still throwing emissions codes? Please specify which "tests" you are referring to?

The truck will complete on board tests of the emissions equipment periodically with certain requirements such as:
gas tanks between 25% and 75% full
truck at operating temp
longer than 15 minute run time
etc.

Are these the "tests" you're referring to?

NO codes of any kinds, I drive all kinds of speed zones during the day, it's been over a weeks of daily driving and still the tests seem to be cycling almost randomly. Why would they show complete, then incomplete the next day or when I start the truck after like 20 minutes? Just seems random. Catalyst, Evap are the primary two culprits.

 

[3bears]

So the truck is, or is not still throwing emissions codes? Please specify which "tests" you are referring to?

The truck will complete on board tests of the emissions equipment periodically with certain requirements such as:
gas tanks between 25% and 75% full
truck at operating temp
longer than 15 minute run time
etc.

Are these the "tests" you're referring to?

disconnect the battery for an hour
turn the key on and off a few times
hit the brakes
turn on the headlights
anything to drain residual power in the ECU
reconnect the battery

then test ( but I left my batt disconcerted overnight)

still no help ?

let us know

I had issues with a code, did everything, then did this...done

 

[Nate_GB]

NO codes of any kinds, I drive all kinds of speed zones during the day, it's been over a weeks of daily driving and still the tests seem to be cycling almost randomly. Why would they show complete, then incomplete the next day or when I start the truck after like 20 minutes? Just seems random. Catalyst, Evap are the primary two culprits.

So the "tests" that I mentioned are the ones you are talking about?

Those tests will complete randomly and be marked by the ECU as "passed" or "incomplete" depending on if the factors of your drive and the factors required to complete the test were met.

The tests being incomplete is normal. If you've driven the truck for 2 weeks, and still no check engine light, I'd say you're good to go and get it smogged. But if you're still worried about it, just take it to one of those places that advertises that you'll pass or they'll give you a free re-test. Assuming they have places like that near you.

 

[Majindan]

So the "tests" that I mentioned are the ones you are talking about?

Those tests will complete randomly and be marked by the ECU as "passed" or "incomplete" depending on if the factors of your drive and the factors required to complete the test were met.

The tests being incomplete is normal. If you've driven the truck for 2 weeks, and still no check engine light, I'd say you're good to go and get it smogged. But if you're still worried about it, just take it to one of those places that advertises that you'll pass or they'll give you a free re-test. Assuming they have places like that near you.

I'll run it through tomorrow, I've driven it a LOT more than the last time the light was one. I'll try disconnecting the battery overnight if it doesn't pass this time. Truck is running perfect too, much better than when I bought it, wish I could just download a ROM and circumvent the entire process, it's bullshit honestly.

 

[Majindan]

Update: emissions test FAILED. Incomplete tests listed, just as I suspected. With no CEL, and no obvious issues otherwise, how am I supposed to troubleshoot? This is seriously making me crazy. Any Toyota mechanics that can chime in?:redbrick:

 

[Majindan]

I'm going to pull the battery for a few hours while I'm at work and see if resetting the whole ECU system works. Other than that, are there any vacuum lines I can double check that would contain a sensor or something??

 

[Majindan]

Crazy thing is, Torque has shown all my tests complete a few days ago, and it's like they randomly reset to incomplete. My battery looks kind of old, but no issues other than it just looks old. Could an old battery cause this?

 

[Freb_mc]

Odd question, do you leave the blue tooth obd2 scanner plugged in all the time? I had an issue with one doing this same thing, test complete and incomplete, over and over again. I cleared the data, and removed the scanner. Drove it to work for a week, no issues, no CEL, and borrowed a Autel scanner at work. No incomplete tests, it was on chevy, so I asked someone about it and He told me that some of the cheap scanners, if left connected will reset the computers memory every time the key is turned on, effectively making your computer re-learn every time you drive it. Now all this was in my 2006 chevy and I have refused to leave it connected all the time now, so I have not experienced this with my 4runner, but maybe It gives you a direction to look.

 

[Buckaroo]

Are you checking for pending codes? The P0420 code sets on two trips. If you satisfy the preconditions and drive cycle, the test will run and set the pending code if it fails - no CEL. Then , key off and, when you satisfy the criteria again and it fails, it will set the permanent code and it will light the CEL.

Possible scenario: I'm not sure how the monitor displays with the pending code but I could imagine that if it runs and passes - the monitor completes and you are happy. It if runs again and it fails, the monitor goes to incomplete, it waits for the second trip. If it passes on the third go, again the monitor goes to complete and you are happy. Maybe you are right on the edge with your Cat efficiency.....

Buckaroo

 

[Majindan]

Well before I replaced the downstream O2, I found a stretch of low speed highway and the cat test completed, CEL tripped. I replaced O2, reset CEL with Torque, and it runs incomplete/complete now regardless of my driving habits and nearly 1k miles driven. Yes I leave the OBDII reader in all the time. Funny thing, after I started the truck this morning after the emission test failed, my radio was set to a static radio station, but the radio memory was still in tact and my truck clock was still correct. I'll leave the reader out for a while and have the battery checked after work. I'm completely dumbfounded.

 

[Majindan]

Are you checking for pending codes? The P0420 code sets on two trips. If you satisfy the preconditions and drive cycle, the test will run and set the pending code if it fails - no CEL. Then , key off and, when you satisfy the criteria again and it fails, it will set the permanent code and it will light the CEL.

Possible scenario: I'm not sure how the monitor displays with the pending code but I could imagine that if it runs and passes - the monitor completes and you are happy. It if runs again and it fails, the monitor goes to incomplete, it waits for the second trip. If it passes on the third go, again the monitor goes to complete and you are happy. Maybe you are right on the edge with your Cat efficiency.....

Buckaroo

Even if it was the CAT, that wouldn't have any effect on the evap test would it? There are no pending codes either.

 

[gamefreakgc]

Crazy thing is, Torque has shown all my tests complete a few days ago, and it's like they randomly reset to incomplete. My battery looks kind of old, but no issues other than it just looks old. Could an old battery cause this?

Yes, if the battery is cutting out it will reset the test. Just like if unplugging the battery will cause the system to need to start over.

If it doesn't come back and stay complete, make sure all wires are connected properly to all the emissions components and there's no damage to the wires. Then test your battery at an auto shop, most places will do it for free (they are trying to sell you a battery). If it checks out ok, you've got either a sensor or a wiring problem.

 

[Buckaroo]

Yes, if the battery is cutting out it will reset the test. Just like if unplugging the battery will cause the system to need to start over.

If it doesn't come back and stay complete, make sure all wires are connected properly to all the emissions components and there's no damage to the wires. Then test your battery at an auto shop, most places will do it for free (they are trying to sell you a battery). If it checks out ok, you've got either a sensor or a wiring problem.

Testing battery is a good first step. If it's good, remove the pos/neg connections, clean the top of the battery with baking soda solution (for good measure) , wire brush the battery terminals and connections and reattach firmly. Also check and clean connection from negative terminal to frame.

Buckaroo

 

[Victor_inox]

Update: emissions test FAILED. Incomplete tests listed, just as I suspected. With no CEL, and no obvious issues otherwise, how am I supposed to troubleshoot? This is seriously making me crazy. Any Toyota mechanics that can chime in?:redbrick:

state emissions or independent shop emissions?

 

[gamefreakgc]

state emissions or independent shop emissions?

If the system shows "Incomplete" on the OBD-II reader, they cannot complete the test so it fails by default. I've had the same situation before.

 

[Victor_inox]

If the system shows "Incomplete" on the OBD-II reader, they cannot complete the test so it fails by default. I've had the same situation before.

Reason I asked is that torque pro is software not used by state testing facilities. Like any software it might be bugs. I'd use another software to confirm.

Sent from my SAMSUNG-SM-G925A using Tapatalk

 

[gamefreakgc]

Reason I asked is that torque pro is software not used by state testing facilities. Like any software it might be bugs. I'd use another software to confirm.

Sent from my SAMSUNG-SM-G925A using Tapatalk

True, but he said his smog test failed at the shop, not just from the bluetooth reader.

 

[Majindan]

It failed at the actual emissions testing facility this morning. I'm disconnecting the battery now on my lunch break to enable the soft ECU reset. I can't find anything online suggesting Torque does anything to cause the test to loop infinitely.