Denso here says their IK20L lasts 30K miles. Click on "Product Specifications".
https://www.densoproducts.com/denso-5358-ik20l-iridium-power-spark-plug#productSpecifications
P0172 Running rich
- Thread starter slybunda
- Start date
https://www.densoproducts.com/denso-5358-ik20l-iridium-power-spark-plug#productSpecifications
hmm would ik20TT be compatible and would they be better / last longer too?
here we go, pics of the spark plugs and the coil packs.
checked my receipts, plugs were fitted in 2015 so done around 20k miles on them. they are denso ik20. the plugs that came with the car were denso sk20r11.
this is the first time in 10 years these plugs have been removed. came out very easily since i used some oil/copper grease or ceramic grease (forgot which one) on the threads when installing them. i dont oil/grease all the threads, i leave about 1cm of threads uncoated thats closer to the tip.
so what story do the plugs tell and where do i go from here? plugs have been numbered, took 2 pics per plug some in bad lighting angle.
car is yet to be driven since iv cleaned the maf and changed the filter, back at work tomorrow so will find out how it drives and will check obd2 when im back at home after work.
checked my receipts, plugs were fitted in 2015 so done around 20k miles on them. they are denso ik20. the plugs that came with the car were denso sk20r11.
this is the first time in 10 years these plugs have been removed. came out very easily since i used some oil/copper grease or ceramic grease (forgot which one) on the threads when installing them. i dont oil/grease all the threads, i leave about 1cm of threads uncoated thats closer to the tip.
so what story do the plugs tell and where do i go from here? plugs have been numbered, took 2 pics per plug some in bad lighting angle.
car is yet to be driven since iv cleaned the maf and changed the filter, back at work tomorrow so will find out how it drives and will check obd2 when im back at home after work.
2,3 and 4 appear to be carbon - aka running rich, which you already knew.
I don't know what to tell you about number one. The ground electrode looks a little rich but the center one looks clean. I have not experienced this so not sure what to tell you on it.
I don't know what to tell you about number one. The ground electrode looks a little rich but the center one looks clean. I have not experienced this so not sure what to tell you on it.
those twin tips are compatible with sk20r11 and the IK20L. They should last longer than 80K miles.
The ends of the ground electrodes facing the center electrode in your IK20s look to me to have a slight chamfer not found in Denso plugs in their website pics. Thus accounting for my perception of a spark gap bigger than what they were originally (0.043"). Just to be sure, check them out with a feeler gauge.
The tan color of the porcelain on plugs 2, 3, 4 does not seem to be abnormal to me. Sure, #1 is whiter but the other 3 don't look that bad.
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Iv been running some redex fuel system cleaner for the last 2 tank fulls mid last week iv added some 2 stroke oil at 300:1 mix to hopefully lubricate the injectors although people are saying I need to be running it at 100:1 mix to actually do anything. But time will tell I guess.
Yes I noticed the chamfer too, maybe it's the ground wearing away?
I was expecting to see plugs totally wet on the tips or fully black which may have pointed to the injectors leaking but now I dunno what to make of it.
After seeing your plugs, I would not suspect anything wrong with your injectors. Why not change your plugs and be done with it? They are not expensive and can eliminate a possible suspect in your chase for the source of your engine trouble code.
If you're still using that 2-stroke oil in your gas, a 1:300 mix is too high. Could be contributing to your rich mixture. (2-stroke oil is a hydrocarbon that burns.) Most folks in BITOG that use 2-stroke oil in their gas stick to a 1:560 or even more dilute ratio. I'd stay away from the 2-stroke oil till you get the code sorted out.
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Does not look like old plugs to me. 3 are coated with carbon from running rich. The other I don't know. None of the electrodes show significant signs of aging. The center electrode still has the proper shape, and the ground electrode is coated not worn.
Any symptoms of misfire? Like a very small shudder under load?
No missing, car runs very smooth same as it did since I bought it 13 years ago.
Can plugs like this cause a rich condition especially at idle?
Driving style is mostly highway these days but couple of years ago it would idle a lot when at the kids hockey training.
These days it's short tripped at 7.5 miles to work then 7.5 miles back home. Mostly highway
Can plugs like this cause a rich condition especially at idle?
Driving style is mostly highway these days but couple of years ago it would idle a lot when at the kids hockey training.
These days it's short tripped at 7.5 miles to work then 7.5 miles back home. Mostly highway
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So we have an update now since the maf clean and filter change.
Idle maf reading has now dropped, before it used to be 2.78g/s but now it's 2.0g/s at idle and ltft at idle is now -9.4 and as revs go up it's getting closer to 0 now. So looks like it's going in the right direction.
The eml is still on and I won't reset it yet but will check readings again at the end if the week and see if there is further change to the readings.
I'm gonna need to change air filter soon iv got an old k&n panel filter in which lets in too much dirt and kills engines over time from what iv read and seen (projectfarm tests).
Idle maf reading has now dropped, before it used to be 2.78g/s but now it's 2.0g/s at idle and ltft at idle is now -9.4 and as revs go up it's getting closer to 0 now. So looks like it's going in the right direction.
The eml is still on and I won't reset it yet but will check readings again at the end if the week and see if there is further change to the readings.
I'm gonna need to change air filter soon iv got an old k&n panel filter in which lets in too much dirt and kills engines over time from what iv read and seen (projectfarm tests).
Great job. Mission accomplished.
This just confirms my statement that a skewed MAF sensor can also cause rich condition not just lean
I wonder if it was the maf sensor itself or the connector. Since I cleaned the connector at the same time too.
The difference in idle flow from 2.78g/s to 2.04g/s is roughly 30%. Which now makes sense on the LTFT at idle being -30 and engine light to be on. The numbers were still fluctuating but did see it drop to 1.9ish too so those saying airflow should be 1g/s per litre of displacement seems to be correct, so my one should be closer to 1.8g/s being a 1.8l engine but not sure at what Rpm that amount at idle is rated at.
Will monitor the trims on Friday and see how they are. Got original Toyota air filter in order too so will replace the k&n one when it arrives, hopefully by the weekend.
This is the first time iv ever seen a maf sensor over read the estimated airflow. Every other time iv seen one fail is always resulted in under reading the airflow rate.
So is this how the system works? ECU first gets a maf reading then throws in the correct amount of fuel it believes should be going in for the reported air flow and then the O2 sensor fine tunes it based in what it sees coming out the exhaust?
The difference in idle flow from 2.78g/s to 2.04g/s is roughly 30%. Which now makes sense on the LTFT at idle being -30 and engine light to be on. The numbers were still fluctuating but did see it drop to 1.9ish too so those saying airflow should be 1g/s per litre of displacement seems to be correct, so my one should be closer to 1.8g/s being a 1.8l engine but not sure at what Rpm that amount at idle is rated at.
Will monitor the trims on Friday and see how they are. Got original Toyota air filter in order too so will replace the k&n one when it arrives, hopefully by the weekend.
This is the first time iv ever seen a maf sensor over read the estimated airflow. Every other time iv seen one fail is always resulted in under reading the airflow rate.
So is this how the system works? ECU first gets a maf reading then throws in the correct amount of fuel it believes should be going in for the reported air flow and then the O2 sensor fine tunes it based in what it sees coming out the exhaust?
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MAF (And / or MAP if so equipped) sensor reads air coming in, the ECU maps the amount of fuel based on that air flow and some other things (like engine temp and who knows what else)
After burn the the Primary A/F sensor (the first 02 sensor, except there not 02 sensors technically anymore) measures the exhaust and either adds or subtracts fuel as needed via the short term fuel trims.
If the Short term fuel trims stay to one side or the other for any length of time (were talking seconds or less) then the ECU adjusts the long term fuel trims as a more permanent offset.
This is the concept of closed loop - measure - control - measure- adjust control - repeat loop.
Checked trims today, at idle showing -10.7. at 2200rpm LTFT and stft are 0ish. So that's a massive improvement of where it would sit at -11 at 4500rpm previously to cleaning maf and changing filter.
Anything I should check that can cause the negative trim at idle? It's around 8c here temp wise too. Checked trims after car was driven for 20mins. Even revving to 1200 rpm gets LTFT down to -6 and stft is +/-3
Anything I should check that can cause the negative trim at idle? It's around 8c here temp wise too. Checked trims after car was driven for 20mins. Even revving to 1200 rpm gets LTFT down to -6 and stft is +/-3
STFT are irrelevant in your case.
LTFT at -10.7% is still not great. Perfection is +/- 5% but you can usually live with +/- 10%. I would drive it a bit more and recheck - it may take a while to re-calibrate the proper trims.
Did you replace the plugs, or just leave them?
Not replaced the plugs yet. Raining all this week so will avoid car work.
It's got a k&n panel filter in it at the moment till my new paper filter arrives. Dunno if k&n filter can affect idle richness.
2 stroke oil still in the tank so waiting for that to go through the system before switching the plugs. Car is at 96k miles was hoping to switch the plugs when I get to an even 100k miles.
It's got a k&n panel filter in it at the moment till my new paper filter arrives. Dunno if k&n filter can affect idle richness.
2 stroke oil still in the tank so waiting for that to go through the system before switching the plugs. Car is at 96k miles was hoping to switch the plugs when I get to an even 100k miles.
The plugs are likely fine, but likely need to burn off a bit, so that might take some miles.
The K&N can dirty a MAF sensor pretty quick, so I would get rid of that.
I don't know what 2 stroke oil does to the Fuel / air ratio. I am guessing its not great.
I would suggest driving it, when fill the tank and maybe a bottle of techron to clean up the injectors.
Hopefully your done and its fixed. Good work.