Honda Odyssey Forum banner

1 - 11 of 11 Posts

·
Registered
Joined
·
83 Posts
Discussion Starter #1
My 2010 Oddy Touring set a P0420 today just after I had a tire pressure sensor replaced, and I can not turn off the Check Engine light or erase the code with my Ultragauge. Both bank 1 and bank 2 downstream O2 sensors seem to be running about a half volt as they should, but the P0420 will not go away. A friend who adjudicates claims for insurance companies and has experience with many vehicles said some manufacturers require that some codes can only be reset by a dealer. Might this P0420 be one of those? Anyone know? I've never had the Ultragauge fail to reset a CEL on any vehicle before, but I've not had a CEL on the Odyssey before this.
 

·
Registered
Joined
·
145 Posts
Never heard of such a thing for P0420 catalyst below threshold. Some scanners cannot reset certain codes yes but my almost 20 year scanner can.

Sent from my SM-N960U using Tapatalk
 

·
Registered
Joined
·
83 Posts
Discussion Starter #3
I have the same model Ultragauge in my 96 Land Rover Discovery and have to reset the CEL almost every time I drive it for cat codes P0420 & P0430 and miss fire codes, and the UG has never failed to turn off the CEL and erase the codes on the Landy..
 

·
Registered
Joined
·
83 Posts
Discussion Starter #4
Update: I disconnected the battery + for an hour this morning and after re-connecting it and entering the Nav and radio codes I re-started the engine and the CEL stayed off and there were no DTC codes set or pending and no errors in the message center. The TPMS was reading all four tires pressures. Fingers crossed that it stays that way.
 

·
Registered
Joined
·
83 Posts
Discussion Starter #5
The CEL came on again later and P0420 was set and again the Ultragauge could not turn off the CEL, but disconnecting the battery again did turn it off and erased the code. Must be an Odyssey thing.
 

·
Registered
Joined
·
230 Posts
The CEL came on again later and P0420 was set and again the Ultragauge could not turn off the CEL, but disconnecting the battery again did turn it off and erased the code. Must be an Odyssey thing.
Have the same code recurring on my wifes Chevy Cruze - My Bluedriver scan tool resets it no problem, funny bc I've heard several people on the chevy forum say it is a permanent code that an obd can't reset.
 

·
Registered
Joined
·
145 Posts
Yes and that's why I'd like to know how long it's taking the OP. Depending on the time it takes, it could indicate a possible faulty sensor or a simple spark plug change with premium fuel. Had this problem come up on a 04 Accord however the light came back after about 500 miles but the driver passed emissions and decided not to worry about it anymore.

Sent from my SM-N960U using Tapatalk
 

·
Registered
Joined
·
1,546 Posts
First, I've also had cars that for some reason won't reset the code.

Second, if the problem is all the time, the code won't reset.

Third, you have a very intermittent problem, and the code should clear itself after you go thru a couple of drive cycles.

Finally, if the car is driving OK, you most likely are OK, and whatever you do, don't dump thousands of dollars chasing a problem that occurs for 30 seconds, four times every year.
 
1 - 11 of 11 Posts
Top