Smog Check failed for Catalyst 'Not Ready'

[MysticGold04]

Need some advice here -

2004 Toyota Highlander 4 cyl with 2AZ-FE
200k + mileage

First year of not passing a CA smog check due to 'Not Ready' for Catalyst.

Smog Tech said to drive it for a while, then come back. Well I drove it to Vegas and back, total of 500+ miles added to the ODO, still not ready- according to my ScanGauge. I pulled the EFI fuse to reset the computer, and have driven it multiple times, about 200 more miles since and the indication is that it is still not ready.

I have been researching extensively about this, and most folks say there could be a number of reasons for this condition.

1. Lazy rear O2 - I last changed this out with an OEM sensor, about 80k miles ago.
2. Faulty Thermostat, not allowing the engine to reach operating temperature
3. Plugs, wires, etc (I have coil on plugs) need to be changed.
4. Battery/Alternator voltage

Via my ScanGauge, I can watch the Coolant temp reach 182-184F and then go down to about 177F and then go back to 182F
while driving, it ranges from 180-195, so I assume my thermostat is working correctly.

The plugs honestly should be changed, but would those really have anything to do with it if the engine is running well?
No fault codes or anything, I checked with my ScanGauge.

Battery/Alternator voltage seems fine... 12.4 volts with the engine off / Ranges from 13.2-14.0 volts while cold, and levels out to about 13.1 - 13.2 while hot.

Has anyone had this experience? What did you do to solve it?
I have done several "drive cycles" for this particular engine, but still is 'Not Ready'

I guess I will start with the least expensive parts first - Coolant temp sensor/thermostat/plugs and go from there.

 

[chainblu]

Does your code reader have the ability to clear the codes? I may be wrong, but I don't think pulling the breaker clears the code, like it used to.

 

[JHZR2]

Can not ready be given due to a front/rear sensor mismatch? If it’s a lazy sensor it’s one thing. If it’s a bad converter that’s another. Your voltage seems low. If it’s a computer demanding that you drive a certain number of cycles (not miles) before ready, perhaps the battery is droppping and resetting the computer without you knowing.

 

[MysticGold04]

Originally Posted By: chainblu
Does your code reader have the ability to clear the codes? I may be wrong, but I don't think pulling the breaker clears the code, like it used to.


Yes, it does... no codes to clear though - If I scan it says NO CODES - NOT READY. I may invest in a new reader that displays the IM Readiness monitors- $30 on Amazon.

 

[MysticGold04]

Originally Posted By: JHZR2
Can not ready be given due to a front/rear sensor mismatch? If it’s a lazy sensor it’s one thing. If it’s a bad converter that’s another. Your voltage seems low. If it’s a computer demanding that you drive a certain number of cycles (not miles) before ready, perhaps the battery is droppping and resetting the computer without you knowing.


I suppose it could be. Battery is a couple years old... Duralast Gold from Autozone.
I've not had any issues since replacement - no battery light - Clock stays constant - no issues to make me think the battery could be the issue - always starts right up without hesitation.

 

[SHOZ]

Monitor the primary and secondary O2 voltages. The primary one should swing from .005V to .0800v or so. The secondary one with a warm engine and steady driving should stay high, above .600v or so. If the second O2 mimics the first O2 swings it's a bad cat.

 

[Anduril]

My Cavalier requires 5 cold starts/warmups to set the CAT monitor. Driving 500 miles straight won't do it, it has to be 5 cold starts so at least 5 different days. Yours might require something similar.

 

[Chris142]

Did you recently disconnect the battery? If not it should have set that monitor a long time ago.

 

[mk378]

Unplug a sensor to make it throw a code deliberately. Then plug the sensor back in and make sure that stored code is remembered when you start and stop several times. If the ECU is not getting backup power, it will go to no codes not ready every time you turn the key off.

 

[SHOZ]

It's usually the evap system that takes forever to set.

 

[Vikas]

Originally Posted By: mk378
Unplug a sensor to make it throw a code deliberately. Then plug the sensor back in and make sure that stored code is remembered when you start and stop several times. If the ECU is not getting backup power, it will go to no codes not ready every time you turn the key off.


There! That is how you generally solve this!

BUT, if that is the only test that is NOT complete, then it will involve lot more trouble shooting. Only Toyota service manual will give the list of the pre-conditions which have to be satisfied before the cat converter test will run. You should make sure there are no pending or stored codes first.

These type of issues need ScannerDanner and/or Eric_South_Main_Auto and/or Ivan_Pine_Hallow_Diagnostic type of person. Your corner shop probably will not be able to figure this out.

 

[eljefino]

Has it been hot? Over 95'F or so and the things might not run.

Toyota (camry) with that motor got a firmware update for the cat, to make the monitor less sensitive.

A spark plug anti-fouler on the rear o2 might just help things along if it's on the borderline and can't make up its mind.

 

[sloinker]

I will venture a WAG. Those running temperatures might be a little low to go to closed loop. Seems most cars need 190-195 degrees to get there. Open loop will inhibit the catalyst readings. Like I said, WAG. Thermostat?

 

[SOHCman]

You are over 200K, time for a new tstat and your o2 sensors are probably getting lazy. Do the plugs as part of a tune up. Plenty of life left in that toyota if you take care of it.

 

[The_Nuke]

For the monitor to move into the READY state, it has to experience several drive cycles with no failed checks. I don’t remember the specifics that define the catalyst’s drive cycles, but just driving for a long time will not satisfy the drive cycle criteria.

Think short trips, errands, anything that involves lots of starting and stopping. That will get you ready more quich

 

[Nick1994]

Voltage sounds pretty low to me, both running and not, not sure if that's the issue though.

 

[Omahaug]

See if you can get your hands on the service manual for that Highlander. Usually the service manual should diagram the exact steps necessary to set the monitor. Then you can try the steps and it will either result in the monitor being set or a code being set.

 

[user52165]

That smog tech did a great disservice telling you to just drive it. It needs a "Drive Cycle". This usually involves a crazy combination driving at certain speeds for a given time, acceleration, deceleration, idling, etc in a very precise pattern, sometimes quite lengthy. Best to print it out and have a passenger read it. One screw up and you have to start it over, or wait a day, etc. Often difficult to complete on public roads unless traffic is very light. This info is available from dealer or a GOOD smog shop. They are required to post sign showing how to find it.............. BAR - Bureau of Auto Repair in CA.

 

[eljefino]

FWIW the EVAP in my Camry took over 1000 miles of road tripping to reset. I kept driving from the hotel to breakfast or a gas station 1st thing in the morning, and it needs a cold start that leads to a full warm up and highway drive with a certain fuel level.

 

[The_Nuke]

“ODB-II Monitors

It's not really the distance you drive it's the way you drive it. The PCM needs to make sure all the emission systems on the vehicle are working and "ready" for operation. So you have to drive in a manner that allows the PCM to run its tests.

Depending on the engine there are usually around 6-8 "emission monitors" and in most states they are all required to be "ready" in order to pass SMOG testing. Here is a drive cycle you can try to expedite the process :

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 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 half 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.”