Code P0420... who's had it?
- Thread starter ryanjl
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I've had the P0420 code
I've had the P0420 code for about 6 months now.. I usually get 300-400 miles before the check engine light come back on after I reset it. However I am too wondering if it is my O2 sensors... I''ve read about how to go about checking them, but It seeme to a very difficult process.
I recently have been gettign P0170, fuel trim malfunction.. I think this could also be attributed to a bad O2 Sensor...
Have any of you had luck gettign rid of P0420 by replacing the O2 sensors?
Eric
I've had the P0420 code for about 6 months now.. I usually get 300-400 miles before the check engine light come back on after I reset it. However I am too wondering if it is my O2 sensors... I''ve read about how to go about checking them, but It seeme to a very difficult process.
I recently have been gettign P0170, fuel trim malfunction.. I think this could also be attributed to a bad O2 Sensor...
Have any of you had luck gettign rid of P0420 by replacing the O2 sensors?
Eric
Have it all the time, just pull the fuse and reset it.....
concretejungle said:
possible sign of bad O2's as well?
Mine tossed the code for a 2nd time this weekend, checked for leaks and all appears fine with the connections....O2's are next on the check list, likely tonite...with almost 150k on the truck it's likely due anyways....
Another 420 code guy
I have 148K on a '95, with orig. oxygen sensors, no exhaust leaks, and newer plugs, filters, etc. I get the PO420 code every 3 months, and turn it off and keep driving.
I drove from Colo Springs to Ft. Collins Sat. and yesterday, and got 15.57 mpg. So, I'm not about to replace the oxygen sensors or do much of anything else until things get a lot uglier. My bro's '94 FZJ gets about 11 mpg, so he's likely due for oxygen sensors.
I have checked the exh. system and can find no leaks.
Steve
I have 148K on a '95, with orig. oxygen sensors, no exhaust leaks, and newer plugs, filters, etc. I get the PO420 code every 3 months, and turn it off and keep driving.
I drove from Colo Springs to Ft. Collins Sat. and yesterday, and got 15.57 mpg. So, I'm not about to replace the oxygen sensors or do much of anything else until things get a lot uglier. My bro's '94 FZJ gets about 11 mpg, so he's likely due for oxygen sensors.
I have checked the exh. system and can find no leaks.
Steve
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I have had this happen twice.
It was last fall on a trip to the beach (about 5 hours driving)
Threw the code after 4 hours on the road (75mph)
had it cleared then threw it again while at the beach (next time it drove it)
I had just put some marvel mystery oil in before the trip and I suspect it may have cleaned up some engine varnish and hit the cats pretty hard.
It has been several months and has not returned.
If it becomes persistant I will change the O2 sensor but was hoping the wait and do them when I have to replace the exhaust.
It was last fall on a trip to the beach (about 5 hours driving)
Threw the code after 4 hours on the road (75mph)
had it cleared then threw it again while at the beach (next time it drove it)
I had just put some marvel mystery oil in before the trip and I suspect it may have cleaned up some engine varnish and hit the cats pretty hard.
It has been several months and has not returned.
If it becomes persistant I will change the O2 sensor but was hoping the wait and do them when I have to replace the exhaust.
I have new universal O2 sensors, not working. Ordered a pair of OEM sensors from cDan today, will post. Here's some graphs of my sensor outputs before and after the universal sensors: https://forum.ih8mud.com/showthread.php?t=75975&page=3
"Code P0420... who's had it?"
Everyone and their grandma's...........
Everyone and their grandma's...........
My rig (1995 with 176K miles) threw the 420 code a couple months ago. I pulled the EFI fuse and reset the MIL, and so far, so good. I am pretty sure mine is due to a leak between the cats. A new gasket is on the short list, but I have had zero time the last couple weeks. Maybe next weekend. I hope the sizeable leak hasn't caused any damage to the flange.
Isn't this one of those codes that indicates your not spending enough time on the trails, and two much time at the malls? Ha!
Sorry, I couldn't resist. Actually I'm wondering if you have a power loss when this light comes on? I had a CEL come on due to having a damaged rear knock sensor, and when it would come on, it seemed to loose at least 1/3 of it's power, which not having regeared yet with 35's really made it sluggish. I'm glad to have finally fixed it.
Good luck.
Sorry, I couldn't resist. Actually I'm wondering if you have a power loss when this light comes on? I had a CEL come on due to having a damaged rear knock sensor, and when it would come on, it seemed to loose at least 1/3 of it's power, which not having regeared yet with 35's really made it sluggish. I'm glad to have finally fixed it.
Good luck.
My rig had that code when I bought it. I cleared the code only to have it return with a couple of O2 sensor errors. Replacing the O2 sensors cleared up all my issues and I haven't had a related code return.
- Craig
- Craig
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Anyone tried this
I am in the process of replacing the gaskets around the CATS and the O2 sensors and a friend told me about these he saw on Ebay.
http://cgi.ebay.com/ebaymotors/MIL-eliminator-oxygen-sensor-simulator-O2-bypass-Toyota_W0QQitemZ8067033590QQcategoryZ33609QQrdZ1QQcmdZViewItem
He said they basically eliminate the rear O2 sensor feedback which is what gives us these PO420 codes.
Anyone tried this or have experience with it? It seems like in theory it would work.
Thanks
Rick B.
I am in the process of replacing the gaskets around the CATS and the O2 sensors and a friend told me about these he saw on Ebay.
http://cgi.ebay.com/ebaymotors/MIL-eliminator-oxygen-sensor-simulator-O2-bypass-Toyota_W0QQitemZ8067033590QQcategoryZ33609QQrdZ1QQcmdZViewItem
He said they basically eliminate the rear O2 sensor feedback which is what gives us these PO420 codes.
Anyone tried this or have experience with it? It seems like in theory it would work.
Thanks
Rick B.
I just replaced the cat gaskets. Really easy, as long as you don't break the bolts. If I had thought about it earlier, I would have replaced the bolts/nuts with stainless pieces, but the stockers were ok.
FWIW, the new gaskets sealed perfectly, no leaks, no codes. I would try this $11, 20 minute fix first, then move on to spending the dough on new cats or some other work-around if you still throw codes.
FWIW, the new gaskets sealed perfectly, no leaks, no codes. I would try this $11, 20 minute fix first, then move on to spending the dough on new cats or some other work-around if you still throw codes.
I think it's a factory defect. PO420 is for bank 1. The same code for bank 2 is PO430. Nobody ever talks about PO430. It's distinctly a bank 1 problem, which indicates a design problem to me. How do we get it addressed by Toyota?
Oops - wrong forum...