It worked a few times in my sisters 2014 Ford explorer long enough to pass inspection a couple times or 3. Not a real permanent fix.
Does catalytic cleaner fuel additive actually work?
- Thread starter guy48065
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I've only had the car for a year. It may have had issues previously.
A counter guy at Napa is suggesting I put O2 sensor spacers in.
How would that work?
O2 sensor spacers make them read a smoother graph (flatter line) if that makes any sense. You can also get spacers with a tiny catalyst in them for cat deletes and other tomfoolery.
A bad 02 sensor can throw catalyst codes. A tired 02 sensor won't react as quickly as a new one, and sometimes it won't put out enough voltage (making the ecu think your engine is perpetually too lean and destroying your fuel economy) both of these problems can throw catalyst codes or fuel trim/system lean codes. If a o2 sensor dies completely (open circuit or the reading never changes or the heating element breaks) then you'll get sensor codes.
Every manufacturer uses their own ECU programming, so some cars decide the cats are bad and blindly trust the 02 sensors and some will throw 02 sensor codes first.
With the second O2 sensor the voltage needs to read above .550v when cruising and not changing like the primary one does. Typically it will run just under the max voltage you see on the primary O2 sensor. This does not apply to cars with a wide band primary O2.
As the sensor wears out it becomes slower to respond. The way Hyundai tests for the cat efficiency is; after warmed up to temp and then turned off. The next time the coolant hits around 150F it will drive the car lean for a few seconds and see how the cat reacts as far as holding a high voltage. This is called testing the saturation of the cat.
If the second O2 is reading less than ~.500v at that time it will fail the test. .450v is cold O2 default voltage output for the 2nd O2. So the slow response of a worn, slow reacting O2 will actually help with the test.
A spacer may help but it will come back sooner or later. All the while you are loosing gas mileage and performance. I went through this for three years before replacing the cat.
When a primary O2s fails completely the ECU will go to default fueling tables and run a bit rich but performance is OK. It sets a code. When the secondary one fails completely or if the heater goes out it just sets a code but should not interfere with the ECU fueling.
When I changed out my second O2 the threads for the OE bung came out with the sensor. Sucked big time. I managed to use a 3/8 NPT pipe thread tap as I could not find a tapered proper O2 threaded tap to start threads with. Once I got some NPT threads cut then I cross threaded a bung extender in and then put in the new O2. Still had bad cat.
Took the O2 out of the top of the cat and poured lacquer thinner through it. Still had bad cat.
As the sensor wears out it becomes slower to respond. The way Hyundai tests for the cat efficiency is; after warmed up to temp and then turned off. The next time the coolant hits around 150F it will drive the car lean for a few seconds and see how the cat reacts as far as holding a high voltage. This is called testing the saturation of the cat.
If the second O2 is reading less than ~.500v at that time it will fail the test. .450v is cold O2 default voltage output for the 2nd O2. So the slow response of a worn, slow reacting O2 will actually help with the test.
A spacer may help but it will come back sooner or later. All the while you are loosing gas mileage and performance. I went through this for three years before replacing the cat.
When a primary O2s fails completely the ECU will go to default fueling tables and run a bit rich but performance is OK. It sets a code. When the secondary one fails completely or if the heater goes out it just sets a code but should not interfere with the ECU fueling.
When I changed out my second O2 the threads for the OE bung came out with the sensor. Sucked big time. I managed to use a 3/8 NPT pipe thread tap as I could not find a tapered proper O2 threaded tap to start threads with. Once I got some NPT threads cut then I cross threaded a bung extender in and then put in the new O2. Still had bad cat.
Took the O2 out of the top of the cat and poured lacquer thinner through it. Still had bad cat.
Okay, here's my story. I had a catalyst efficiency code if I drove slowly for a while. (more than an hour) one day i got a cel after flooring it up an on ramp. It was bank 1 lean. I cleared the code, and went for a quick drive while watching the live data. When I let off the throttle (to a cruising position) at the end of the on ramp, one of the front 02 sensors would drop to 0.01v and stay there for a long while before coming back to life and reading rich until the fuel trims dropped again. I replaced the front 02 sensors, and now that they react faster the rear 02 sensor doesn't slowly wander up and down anymore, and my catalyst codes and lean codes are gone.
Modern FI engines will cut fuel injectors to idle fuel trims, usually called Coasting Fuel Shut Off or something. This shows up as 0v on the Primary O2 when coasting in gear. Does not do this in neutral. Great way to help your gas mileage if you know how it works.
Yes. Deceleration Fuel Cut Off or DFCO.
I know, but once I got back on the throttle, the 02 sensor wouldn't read that there was fuel again. The engine was smooth and powerful, so I didn't think 3 cylinders weren't getting fuel.
I'm also not 100% sure my car has dfco. It is a design from the late 90s
If the O2 sensor sends no voltage when it should you will get a DTC of slow or no activity. Won't go away until you fix it but will clear it self when fixed. You can clear it but the second time you start the engine it will come back.
How many miles?
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- Feb 9, 2023
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I tried risoline ( think that's the name) version of cataclean. I followed the directions exactly and it didn't do squat.
Lights still on 25k later, fortunately I don't need emissions.
Lights still on 25k later, fortunately I don't need emissions.
I ran two rounds of cataclean through my 2003 Corolla with 213K after changing out the spark plugs (nearly due for replacement anyway) to try and clear a p0420. Neither changing the spark plugs, nor the cataclean prevented the CEL from coming back, but the butt dyno did register a bit better acceleration. I’ve got new Denso O2 sensors waiting to be installed.
I recently used Cataclean in my 190k-mile Tacoma... the truck didn't have a CEL/codes or drivability issues so this was just for maintenance purposes. Cataclean claims to clean out the matrix inside the cat as well as clean the O2 sensors, combustion chambers and fuel injectors. Also I ran the Cataclean for 50 miles when the instructions say run it 15 miles before refueling (there is no danger in running it longer). I noticed a silky smooth idle and slightly better throttle response afterward, but the fuel economy is the same. I guess it works?
Something you add to the gas may clean up the combustion chamber and plugs so the is more complete combustion, thus lowering the load on the cat. This may make the car run better and temporarily turn off the code.
But no way is it doing anything inside the cat as it would have to not be combusted to get there as a liquid. Maybe some magic fumes are generated that cleans out clogged cats?
Or do a SeaFoam like treatment directly into the intake and stall the motor out due to too rich, that would get liquid into the cat.
But I didn't have any luck washing out the cat when I had good access and orientation.
But no way is it doing anything inside the cat as it would have to not be combusted to get there as a liquid. Maybe some magic fumes are generated that cleans out clogged cats?
Or do a SeaFoam like treatment directly into the intake and stall the motor out due to too rich, that would get liquid into the cat.
But I didn't have any luck washing out the cat when I had good access and orientation.
This little guy works...
If the new O2 sensors do not cure the issue --- go to Rock Auto site & get the CC you need. Remember to use the Rock Auto discount code on Sales/Rebates forums on here. The 5% off usually covers the shipping or most of it.
It didn't do anything in my daughters '08 CRV. Waiting for shop to call me back. They are working with their parts supply house to cover the warranty as it's less than 2 years old. Her cat got stolen and factory one was on a minimum 3-4 back order, shop had called and I did also to many dealers. Shop got what was available which I think was Magnaflow so I could get her car back to her for school/work.
