OBDII Checks not complete after 3000 miles of driving

smetzger

03 P5 (x2), 09 Miata, 07 Mazda3, 13 Fit, 09 Ody
So, I had unhooked my battery to do the Man Trans Motor Mount and after 3000 miles the OBD II checks still are not complete.
I have had a pending P0421 for the last 1000 miles or so. CEL has never come on and P0421 just stays pending.

Any ideas on how to solve this?
 
This is what the service manual says,..

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You may have a deteriorating pre-cat or upstream O2 sensor.

The code needs to have 2 consecutive drive cycles to turn on the CEL and that hasn't happened yet.

That could mean that things warm up and start working, but I don't know how long the ECU saves the initial pending code.

Try rubbing the code and see if it comes back, keeping in mind the monitoring conditions so you can get it to test.
Then the next best option is to replace the upstream O2 sensor.
If that doesn't work, then the next step would be installing that O2 sensor into a non-fouler to eliminate the code so you don't have to replace your pre-cat because they are expensive and a PITA to replace.
(Everyone with a header has a non-fouler)


 
Thanks, I had previously gotten this code as a pending and as a confirmed (cleared and did not come back).

So, I think it's time to replace the upper 02 sensor. Hopefully the old one won't be too much trouble to remove. If the code still comes back with a new 02 sensor I'll try the non-fouler work around.

At least I'll be getting another RockAuto magnet for my collection :rolleyes:
 
So, I think it's time to replace the upper 02 sensor. Hopefully the old one won't be too much trouble to remove.

Cut the wire off the old O2 sensor, and/or smash the ceramic end off the old sensor so that you can fit a deep or regular socket on the sensor.

An O2 sensor socket has a slit in it for the wire, but there can be so much torque on the socket that it opens up and strips the sensor flats.

You can install the new sensor with anything, even an open ended wrench.
Some antiseize on the threads is a good idea, especially if you have to remove it again to install it in a non-fouler.

Make sure that you buy a sensor with a smaller end on it to fit your non-fouler if you end up needing one.

This is the part that I broke off my old sensor,..

20210529_171156.jpg
 
Thanks, I had previously gotten this code as a pending and as a confirmed (cleared and did not come back).

So, I think it's time to replace the upper 02 sensor. Hopefully the old one won't be too much trouble to remove. If the code still comes back with a new 02 sensor I'll try the non-fouler work around.

At least I'll be getting another RockAuto magnet for my collection :rolleyes:
When it comes to O2 sensors for my P5, "OBD-II" stands for "Only Buy Denso... two of 'em!" :pSorry, I'm halfway through my Friday evening bourbon and it only gets worse from here. But seriously, I do like the two Denso O2 sensors I installed on my car, and they come with a packet of anti-seize. RockAuto has them both, but I think I found one of them cheaper on eBay. @pcb had to cut and splice one of his as it wasn't a direct fit and you can find his post about this on the forum. Unless his was a simply universal part, you may want to shell out for a name brand.

Do you know if neither of your O2 sensors been replaced? If not, they are pretty old by now. My car's had a pretty good life and I had to replace both of them a few years back as they were throwing codes.
 
I did get it off w/o any issues.
I had replace the top one a few years ago. Bottom one is at least 5 years probably older.

Still waiting for the I/M OBDII checks to complete.
 
I did get it off w/o any issues.
I had replace the top one a few years ago. Bottom one is at least 5 years probably older.

Still waiting for the I/M OBDII checks to complete.
If you're talking about the Readiness Monitor checks, my CAT and EVAP monitors were taking forever to be Ready and I failed emissions testing twice. I had to drive at prescribed speeds to get the CAT monitor to be Ready, which luckily happened on my first try.

wUmST9wdl7phdCOQvNVHRuoNtIt-KDTcITwtcE2t2MRrm90Oz2yUIEXzpDkXrD3mz9OzKodEET4c-slj93Qlm5MulpnN89oMzl4VoKA3kvWE-301w2wHUNoUdYLIPb9mpGdFhkfEeaw8eR_n7R7q7zQdzuu_0z4F4SIN-Aytp2VqlHvO94NWWPT2PeEJGmBxxjFSFHyTO8Z533cYUGVlDQkkcxV0eT6XQw5RjMDSFVbtCcPTp4_uo_HHtzfqVPpSAJu_PDOoQe7J8aP930dDxsYwtH2qiFqCrsbdXyz0aMFzjFGobe_Djf7R9IBvxNeXVzyj0ZOl_62ortsQl43PlABcpG3UJpPfJT0oR6QgNti4BDI43lJfjY_u-qHgti6cE0ng5wDoknGN45HTSN8Bh8IV28IB1Y-dcDvRTNPEhaJRZoQF7DB5T0Fp8ffyHUNeFrkOJicdq0X3NuiNHBnDoprIMirgyDB4LhYp2kX5BXg6jMedn-YcW-Zd5GuHIa8Bzh7kArE4PJINCSanem-0B7BnkllE2a3dQbvAQCHKdjoJHWIY3JKqR6FYEW9Eh8MFsLnv6ejiv9dZkGF99IlByk-Ae0pMX1qBdf7RI2CuIXW3LJot_xPn4KA1-pTfkeFinwEmUUxmVEBbCCCtqPrYFgO8UZLjN6z6tJE92wZn3XuQEnGprIwoN9tOX_wixVkiXsFgMNwX59cYjcX8dubMcxtHF32NsfBW3whz_6O4O9Sx0X7V43xhOp_LFGzHV2z4GTCDUjWCp47g9exeWc-OwWzxSitSxyhxl3lmKSvyZfkmX7FxHWyyeDjbWc8iUs1oYb_-bf4qJ1pfnjSAHxTMktxFLbXBs2HdOBSfcZgcWkxjBb0bHlT_w85aGH-uoBNYy4kTwwqLfOqCQFoOpXaCVMgju4reDPQDoonD5kjNw_BzkQWeIA=w1858-h872-s-no
 
If you're talking about the Readiness Monitor checks, my CAT and EVAP monitors were taking forever to be Ready and I failed emissions testing twice. I had to drive at prescribed speeds to get the CAT monitor to be Ready, which luckily happened on my first try.

wUmST9wdl7phdCOQvNVHRuoNtIt-KDTcITwtcE2t2MRrm90Oz2yUIEXzpDkXrD3mz9OzKodEET4c-slj93Qlm5MulpnN89oMzl4VoKA3kvWE-301w2wHUNoUdYLIPb9mpGdFhkfEeaw8eR_n7R7q7zQdzuu_0z4F4SIN-Aytp2VqlHvO94NWWPT2PeEJGmBxxjFSFHyTO8Z533cYUGVlDQkkcxV0eT6XQw5RjMDSFVbtCcPTp4_uo_HHtzfqVPpSAJu_PDOoQe7J8aP930dDxsYwtH2qiFqCrsbdXyz0aMFzjFGobe_Djf7R9IBvxNeXVzyj0ZOl_62ortsQl43PlABcpG3UJpPfJT0oR6QgNti4BDI43lJfjY_u-qHgti6cE0ng5wDoknGN45HTSN8Bh8IV28IB1Y-dcDvRTNPEhaJRZoQF7DB5T0Fp8ffyHUNeFrkOJicdq0X3NuiNHBnDoprIMirgyDB4LhYp2kX5BXg6jMedn-YcW-Zd5GuHIa8Bzh7kArE4PJINCSanem-0B7BnkllE2a3dQbvAQCHKdjoJHWIY3JKqR6FYEW9Eh8MFsLnv6ejiv9dZkGF99IlByk-Ae0pMX1qBdf7RI2CuIXW3LJot_xPn4KA1-pTfkeFinwEmUUxmVEBbCCCtqPrYFgO8UZLjN6z6tJE92wZn3XuQEnGprIwoN9tOX_wixVkiXsFgMNwX59cYjcX8dubMcxtHF32NsfBW3whz_6O4O9Sx0X7V43xhOp_LFGzHV2z4GTCDUjWCp47g9exeWc-OwWzxSitSxyhxl3lmKSvyZfkmX7FxHWyyeDjbWc8iUs1oYb_-bf4qJ1pfnjSAHxTMktxFLbXBs2HdOBSfcZgcWkxjBb0bHlT_w85aGH-uoBNYy4kTwwqLfOqCQFoOpXaCVMgju4reDPQDoonD5kjNw_BzkQWeIA=w1858-h872-s-no
Just checked again today and readiness monitor checks are not complete yet. But no codes.

Yes, here is the drive cycle....
Mode 1
1) Start vehicle andhttps://www.ebay.com (commissions earned) min.
2) Rev engine in neutral or park to 2300-2700 rpm for 15 seconds
3)Rev engine in neutral or park to 3800-4200 rpm for 15 seconds
4)Idle engine for 20 seconds with cooling fan stopped.

Mode 2 (EGR)
  1. Mode 1 first
  2. 50-60 mph for 1 min, 5th gear

Mode 3 (H02S heater. HO2S, and TWC)
  1. Drive Mode 1
  2. Driving condition before constant speed is not specified
  3. 50 mph for 1 min, 5th gear
  4. 40-60 mph for 4 min, 5th gear

Mode 4 (EVAP)
  1. Barometric pressure 72.2kPa or higher
  2. 50 - 140 F
  3. fuel tank level: 0.5v - 2.5v
  4. engine coolant temp 14F - upper limit determined by barometric pressure
  5. start engine and race at 3500 rpm to warm up completely - 3.5 minutes
  6. 20 second acceleration to…
  7. 40-60mph for 2 min


I generally do Mode 1 and then just drive until checks are complete. I suspect it takes awhile because I rarely am going 50-60mph. Plan is to keep driving and checking. If I get a notice from MD that I need to have my emissions tested, then I'll drive around at 50-60mph in 5th gear for 20 minutes.
 
Well... I am at 1200 miles and the Catalyst Monitor is still Incomplete.
Emissions is due in about a month.
No CELL, no pending codes.

I did try driving in 5th gear for about 30 minutes this weekend. Still not complete.

Only thing I can think to do is to put the non-fowler in on the lower (this is where I had to put it on my other Protege's), do the drive cycle and see what happens.

Any other ideas?
 
When I replaced my downstream O2 sensor, I cleared the code that day.

I followed this,..

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Screenshot_20230404-142720_Acrobat for Samsung.jpg
Screenshot_20230404-142919_Acrobat for Samsung.jpg



The hardest part for me was revving the engine at 5000 RPMS in neutral for 15 seconds.

That just seemed so wrong.
How to blow up your car in 15 seconds flat !! 😂
 
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That's an Italian tune up and is probably a good idea to be done every now and then to help clear out that EGR.

Yes, that is drive mode 1. I did that and then if you look at the other drive modes they are all drive at 50 in 5th gear or 40-60 in 5th gear, or accelerate up to 40-60 and then drive in 5th gear.

So, I have done all the different drive modes.
 
Update...

I could not get the lower OBDII sensor off :(

I did put an extender on the upper one (but that one is new and I don't thin kit is the issue.
Did Drive Mode 1 and then drove at @ 50 mph for about 30 minutes. Catalyst Mon still not complete...

Plan...
1) Just keep driving it
2) Emissions is due April 28. If its doesn't sort itself out by then I'll ask for an extension
3) If I have to eventually get tested and it fails. I'll then take it to a shop. There is a maximum you need to pay a shop to fix an emissions issue, so I'll have that going for me.

Will update as things progress.
 
Update...
1) got an extension from April 28 to Sep 6
2) Still hasn't sorted itself out... no codes... but CAT Mon is still Pending...
3) Got another extension till Jan 10
- filled it out online, not sure why they keep granting me extensions, fine by me though
 
Posting for posterity in case other states have similar rules: In Texas, you can't pass emissions if you have an active CEL of course, but you can pass with one *monitor* showing as Not Ready. I had a total of two monitors that were Not Ready (above), and was able to clear one of them with the prescribed drive cycle. I then got the car inspected and the other monitor became Ready on its own at some point later.

Remember Effective October 15, 2008:
For vehicles year model 2001 and newer, we allow one (1) non-continuous monitor to be "Not Ready" and still pass the test, but two (2) or more "Not Ready" readings will cause the vehicle to fail.
 
Posting for posterity in case other states have similar rules: In Texas, you can't pass emissions if you have an active CEL of course, but you can pass with one *monitor* showing as Not Ready. I had a total of two monitors that were Not Ready (above), and was able to clear one of them with the prescribed drive cycle. I then got the car inspected and the other monitor became Ready on its own at some point later.

Remember Effective October 15, 2008:
For vehicles year model 2001 and newer, we allow one (1) non-continuous monitor to be "Not Ready" and still pass the test, but two (2) or more "Not Ready" readings will cause the vehicle to fail.

Yeah I won't pass in MD until they all are checked.
Plan is to keep getting extensions until they don't give me one.
Then fail it.
At this point if I spend x dollars (not sure what it is) and it doesn't fix it then they will pass me. So, I'll take it to a shop and have them wrestle with the lower o2 sensor.
 
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