I'm really fed up with my P0420 code
01-25-2011, 01:22 PM
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I'm really fed up with my P0420 code
I'll start from the beginning.
-While parking in the winter of 09 I ripped off my O2 sensor from my cat over rough snow. This triggered a P0420 code
-I drove without it in place for about 2 months before I bought a new sensor.
-I was getting poor gas mileage
After I replaced the senor I started to get good gas mileage again but about two weeks later the same P0420 error code came on. I went over to a mechanic to get it diagnosed. He took temp readings around my cat and said that there was a 200 degree difference in the cat. It was much hotter in front then out the back of it. He recommended I get a new cat.
I drove for maybe 6 months on my old cat, I noticed no difference in performance and I was getting 32mpg.
Around 8 months ago I replaced the cat with a Man***low universal fit one. The error code went away for 2 days then came back. At that point I replaced both O2 sensors, one in the cat, one in the exhaust headers. I reset the CEL code but the same error code keeps coming back. After this I did not drive the car for all of the summer, had it parked with a stripped spark plug. After I fixed the issue late November, the same error code came back on.
As of this week, I installed a spark plug non-fouler into the cat, reset the CEL and after only 15 minutes of driving the check engine light came back on with what I assume is the same error code.
What is left for me to diagnose? I'm getting poor gas mileage again and probably worse performance.
I have not tested or replaced the MAS, damn thing is expensive and no junkyards in my area have my car.
Autozone gives me 4 possible issues, A/F mixture, something about ignition, bad cat, bad O2 sensor. When I google the error code I see a few more problems such as a bad CTS or retarded timing. Can timing be adjusted on non-dizzy engines? Would a bad CTS cause this error code?
-While parking in the winter of 09 I ripped off my O2 sensor from my cat over rough snow. This triggered a P0420 code
-I drove without it in place for about 2 months before I bought a new sensor.
-I was getting poor gas mileage
After I replaced the senor I started to get good gas mileage again but about two weeks later the same P0420 error code came on. I went over to a mechanic to get it diagnosed. He took temp readings around my cat and said that there was a 200 degree difference in the cat. It was much hotter in front then out the back of it. He recommended I get a new cat.
I drove for maybe 6 months on my old cat, I noticed no difference in performance and I was getting 32mpg.
Around 8 months ago I replaced the cat with a Man***low universal fit one. The error code went away for 2 days then came back. At that point I replaced both O2 sensors, one in the cat, one in the exhaust headers. I reset the CEL code but the same error code keeps coming back. After this I did not drive the car for all of the summer, had it parked with a stripped spark plug. After I fixed the issue late November, the same error code came back on.
As of this week, I installed a spark plug non-fouler into the cat, reset the CEL and after only 15 minutes of driving the check engine light came back on with what I assume is the same error code.
What is left for me to diagnose? I'm getting poor gas mileage again and probably worse performance.
I have not tested or replaced the MAS, damn thing is expensive and no junkyards in my area have my car.
Autozone gives me 4 possible issues, A/F mixture, something about ignition, bad cat, bad O2 sensor. When I google the error code I see a few more problems such as a bad CTS or retarded timing. Can timing be adjusted on non-dizzy engines? Would a bad CTS cause this error code?
01-25-2011, 01:33 PM
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Re: I'm really fed up with my P0420 code
I had the timing belt replaced about 4 years ago at 120k. Its at 169k right now.
Can a timing light be used on this engine?
Can a timing light be used on this engine?
01-25-2011, 04:40 PM
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Re: I'm really fed up with my P0420 code
Data: Ignition timing.
Description: Ignition timing is the ignition advance angle set by the ECM/PCM. The ECM/PCM matches ignition timing to the driving conditions.
Operating Value: At idle speed: 8° ± 2° BTDC when the SCS service line is jumped with the HDS.
Freeze data: NO
Description: Ignition timing is the ignition advance angle set by the ECM/PCM. The ECM/PCM matches ignition timing to the driving conditions.
Operating Value: At idle speed: 8° ± 2° BTDC when the SCS service line is jumped with the HDS.
Freeze data: NO
There are 4 marks on the crank pulley. When standing on the driver side of the car looking down on the pulley, the mark farthest to the right is the mark for TDC (Top Dead Center). The three marks on the left are for the spark timing. Of these three the mark in the center should align with the arrows/triangles on the timing belt cover when the engine is running and a timing light is shining on the crank pulley. The outer two marks represent Honda's tolerances for the ignition timing. As you look at the cam pulley the correct mark is at 7 o'clock with the two other marks at 3 & 9 o'clock positions. make sure you have correc timing, honda have "O" tolerance when it come to piston and the valves meets.
01-25-2011, 06:21 PM
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Re: I'm really fed up with my P0420 code
p0420 catalyst efficiency below threshold. means you need a new cat. recommend getting a oem one pricey but less of a headache.
01-25-2011, 06:36 PM
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01-25-2011, 06:55 PM
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Re: I'm really fed up with my P0420 code
You can space out the secondary O2 sensor so it's not reading the exhaust gases therefore, not setting the P0420 code.
Check this thread:
https://honda-tech.com/forums/acura-integra-type-r-8/spark-plug-non-fouler-1841240/
Check this thread:
https://honda-tech.com/forums/acura-integra-type-r-8/spark-plug-non-fouler-1841240/
01-25-2011, 07:39 PM
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Re: I'm really fed up with my P0420 code
I really dont see the physical difference between the oem cat and the universal magnaflow I put in. Same length, two brick design.
Cant get a cat from a junkyard, no one else is selling one.
I just tried the spark plug thing, it didnt seem to work.
Cant get a cat from a junkyard, no one else is selling one.
I just tried the spark plug thing, it didnt seem to work.
01-26-2011, 04:41 PM
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Re: I'm really fed up with my P0420 code
any cheaper alternatives though? like fooling that damn O2 sensor, or maybe a JDM ECU that doesnt require a cat or flashing my ECU?
01-28-2011, 05:12 AM
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Re: I'm really fed up with my P0420 code
ok ran into a problem of the same sort working on peoples cars check the voltage on the o2 sensor to ensure when it was riped of it did strech any wiring
01-28-2011, 10:48 AM
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Re: I'm really fed up with my P0420 code
Hmm, it got ripped off at the plug end of the O2 sensor. the other end was secured with a tie. I should check the other end of it.
Besides a physical inspection, what should I check with a voltmeter on those lines? Are they all grounded?
Besides a physical inspection, what should I check with a voltmeter on those lines? Are they all grounded?
01-31-2011, 01:10 AM
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Re: I'm really fed up with my P0420 code
apparently I didnt drain the caps when I unplugged my batt.
anyway, 40 miles later the check engine light went off and its been off for another 100 miles. I think i'm already getting better gas mileage, fuel gauge hasnt dropped at 140 miles in, it usually starts to go down around 120 and when I was getting poor gas mileage it went down around 80.
and I cant tell but I think the car gained back some hp. I was told that when that error code is triggered the engine runs 15% slower, but I cant tell with that little amount of power.
anyway, 40 miles later the check engine light went off and its been off for another 100 miles. I think i'm already getting better gas mileage, fuel gauge hasnt dropped at 140 miles in, it usually starts to go down around 120 and when I was getting poor gas mileage it went down around 80.
and I cant tell but I think the car gained back some hp. I was told that when that error code is triggered the engine runs 15% slower, but I cant tell with that little amount of power.
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