It could be that the downstream O2 sensor just needs to be cleaned so that the sensor-ness can be restored. I imagine a powered wire wheel of some sorts would be a good try. Maybe even a stainless steel wire wheel so as to avoid inter-granular corrosion being introduced to the sensor.
P0420 Catalyst System Efficiency Below Threshold
- Thread starter kschachn
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A P0420 or P0430 doesn't mean the cats have completely failed, it just means they are not operating at their intended efficiency level. IIRC, a 5% drop in efficiency will trigger a P0420. Before replacing your cats, check your fuel injectors and fuel pressure regulator. Leaking injectors will not only cause the engine to run exceptionally rich, but will also kill cats just as a lean condition would, which increases combustion temperatures. Check for vacuum leaks, a higher than normal MAF voltage, etc. which also causes the engine to run rich. Check for any exhaust leaks between the front and rear oxygen sensors. A very minor leak is enough to throw a code.
Gently tap the catalyst and make sure nothing is loose/rattling inside with no rust or holes. Get a digital high temperature infrared thermometer and run the engine to operating temperature. At 2,500 rpm, check the temperatures at the inlet and the outlet. If the reading is ~100 F higher at the outlet, your catalyst is probably fine. At idle, this'll be about 30 F to 50 F.
Gently tap the catalyst and make sure nothing is loose/rattling inside with no rust or holes. Get a digital high temperature infrared thermometer and run the engine to operating temperature. At 2,500 rpm, check the temperatures at the inlet and the outlet. If the reading is ~100 F higher at the outlet, your catalyst is probably fine. At idle, this'll be about 30 F to 50 F.
I got a P420 code a month or two ago. Most of my driving is short distance with no hard runs. I took the car out on a good hard highway run, to blow it out. I haven't had the code since. Just something easy to try, if the car sees mostly loafing along type driving.
Originally Posted By: GMBoy
Throw a spacer (spark plug anti-fouler) on that after cat oxygen sensor and problem fixed. Buy the deep ones and you usually don't have to drill them out. Double them up too.
Yepx10
Or purchase a spacer:
https://www.amazon.com/O2-Sensor-Spacer-Adapter-Extender/dp/B00CZFCPQU
Throw a spacer (spark plug anti-fouler) on that after cat oxygen sensor and problem fixed. Buy the deep ones and you usually don't have to drill them out. Double them up too.
Yepx10
Or purchase a spacer:
https://www.amazon.com/O2-Sensor-Spacer-Adapter-Extender/dp/B00CZFCPQU
Originally Posted By: MarkM66
Originally Posted By: GMBoy
Throw a spacer (spark plug anti-fouler) on that after cat oxygen sensor and problem fixed. Buy the deep ones and you usually don't have to drill them out. Double them up too.
Yepx10
Or purchase a spacer:
https://www.amazon.com/O2-Sensor-Spacer-Adapter-Extender/dp/B00CZFCPQU
THANKS!!!! I have done probably 30-40 O2 spacers and each time I used a spark plug non-fouler and man you just saved me a bit of labor! Many thanks - I am ordering a few now.
Originally Posted By: GMBoy
Throw a spacer (spark plug anti-fouler) on that after cat oxygen sensor and problem fixed. Buy the deep ones and you usually don't have to drill them out. Double them up too.
Yepx10
Or purchase a spacer:
https://www.amazon.com/O2-Sensor-Spacer-Adapter-Extender/dp/B00CZFCPQU
THANKS!!!! I have done probably 30-40 O2 spacers and each time I used a spark plug non-fouler and man you just saved me a bit of labor! Many thanks - I am ordering a few now.
I didn't even know these existed. Thanks!
Gonna make a killing up here off friends with bad or hollowed out cats!
Gonna make a killing up here off friends with bad or hollowed out cats!
Originally Posted By: GMBoy
Originally Posted By: MarkM66
Originally Posted By: GMBoy
Throw a spacer (spark plug anti-fouler) on that after cat oxygen sensor and problem fixed. Buy the deep ones and you usually don't have to drill them out. Double them up too.
Yepx10
Or purchase a spacer:
https://www.amazon.com/O2-Sensor-Spacer-Adapter-Extender/dp/B00CZFCPQU
THANKS!!!! I have done probably 30-40 O2 spacers and each time I used a spark plug non-fouler and man you just saved me a bit of labor! Many thanks - I am ordering a few now.
Sure thing. Also check Ebay, even cheaper.
Originally Posted By: MarkM66
Originally Posted By: GMBoy
Throw a spacer (spark plug anti-fouler) on that after cat oxygen sensor and problem fixed. Buy the deep ones and you usually don't have to drill them out. Double them up too.
Yepx10
Or purchase a spacer:
https://www.amazon.com/O2-Sensor-Spacer-Adapter-Extender/dp/B00CZFCPQU
THANKS!!!! I have done probably 30-40 O2 spacers and each time I used a spark plug non-fouler and man you just saved me a bit of labor! Many thanks - I am ordering a few now.
Sure thing. Also check Ebay, even cheaper.
So the purpose of these spacers is to avoid codes coming up? Does it bring mpg and emissions back to normal or is it a band aid solution to avoid hundreds in buying a fresh cat to restore performance?
Just want to know because I keep getting a b1s1 code I believe which is the AFR sensor p2238. Happens randomly once every few months and goes away on its own unless I clear it myself. What gives? Bad cat or sensor? I will also be monitoring the post cat sensor to see how the catalytic converter is working because I've seen the data in the first post before, just didn't know what it meant.
Just want to know because I keep getting a b1s1 code I believe which is the AFR sensor p2238. Happens randomly once every few months and goes away on its own unless I clear it myself. What gives? Bad cat or sensor? I will also be monitoring the post cat sensor to see how the catalytic converter is working because I've seen the data in the first post before, just didn't know what it meant.
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