Go Back   EcoModder Forum > EcoModding > Off-Topic Tech
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 04-08-2019, 11:29 AM   #71 (permalink)
Cyborg ECU
 
California98Civic's Avatar
 
Join Date: Mar 2011
Location: Coastal Southern California
Posts: 5,219

Black and Green - '98 Honda Civic DX Coupe
Team Honda
90 day: 64.33 mpg (US)

Black and Red - '00 Nashbar Custom built eBike
90 day: 3671.43 mpg (US)
Thanks: 1,859
Thanked 1,555 Times in 1,058 Posts
Quote:
Originally Posted by Piotrsko View Post
Unburned fuels tend to be like creosote in a wood fireplace. Otherwise how do you get clogged cats? Typical solution is to increase temperatures like a self cleaning house oven.

It is not improbable that this coating could fall off and clog a passage.
That's really interesting. I did clean the intake and exhaust passages to the extent that I could reach them when I took the head off. And I also cleaned the surfaces of two of the Pistons, those that were easy to reach. But the other two Pistons remain quite dirty. I suppose something could have flaked off there or from somewhere deep within the exhaust manifold that I couldn't reach. At any rate the PO420 code has not yet repeated.

__________________


See my car's mod & maintenance thread and my electric bicycle's thread for ongoing projects. I will rebuild Black and Green over decades as parts die, until it becomes a different car of roughly the same shape and color. My minimum fuel economy goal is 55 mpg while averaging posted speed limits. I generally top 60 mpg. See also my Honda manual transmission specs thread.

  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 08-22-2019, 11:37 PM   #72 (permalink)
Master EcoModder
 
Join Date: Aug 2018
Location: USA
Posts: 288

Jeep - '97 Jeep Cherokee Sport
90 day: 19.36 mpg (US)
Thanks: 76
Thanked 48 Times in 46 Posts
One of my vehicles threw a P0420 code today, and started overheating about two hours later (coming home from a trip). Is this indicative of a clogged cat? I'm wondering if this procedure would also work on a clogged cat after all of the pieces have been removed.

Another related question that may have been answered: are there proper methods for disposing of the leftover mixture after the cat is cleaned?
  Reply With Quote
Old 08-22-2019, 11:55 PM   #73 (permalink)
Cyborg ECU
 
California98Civic's Avatar
 
Join Date: Mar 2011
Location: Coastal Southern California
Posts: 5,219

Black and Green - '98 Honda Civic DX Coupe
Team Honda
90 day: 64.33 mpg (US)

Black and Red - '00 Nashbar Custom built eBike
90 day: 3671.43 mpg (US)
Thanks: 1,859
Thanked 1,555 Times in 1,058 Posts
Quote:
Originally Posted by Taylor95 View Post
One of my vehicles threw a P0420 code today, and started overheating about two hours later (coming home from a trip). Is this indicative of a clogged cat? I'm wondering if this procedure would also work on a clogged cat after all of the pieces have been removed.

Another related question that may have been answered: are there proper methods for disposing of the leftover mixture after the cat is cleaned?
I disposed of my leftovers taking it with old coolant and such to our hazardous waste facility. Different states will vary.

On your core question, ... overheating is not a symptom of a P0420. However, a failing head gasket could cause an overheating situation and perhaps set off the inefficient CAT Code P0420 if the engine begins burning enough coolant and oil. It's also possible that the two events are completely unrelated. I would start by investigating the cause of the overheating.
__________________


See my car's mod & maintenance thread and my electric bicycle's thread for ongoing projects. I will rebuild Black and Green over decades as parts die, until it becomes a different car of roughly the same shape and color. My minimum fuel economy goal is 55 mpg while averaging posted speed limits. I generally top 60 mpg. See also my Honda manual transmission specs thread.

  Reply With Quote
The Following 2 Users Say Thank You to California98Civic For This Useful Post:
Taylor95 (08-22-2019), Xist (08-23-2019)
Old 08-23-2019, 12:02 AM   #74 (permalink)
Master EcoModder
 
Join Date: Aug 2018
Location: USA
Posts: 288

Jeep - '97 Jeep Cherokee Sport
90 day: 19.36 mpg (US)
Thanks: 76
Thanked 48 Times in 46 Posts
That would be quite the coincidence for the events to happen on the same trip but be unrelated. Possible though.

The headgasket can be ruled out because that was replaced around 20k miles ago. If the overheating is caused by the cooling system, then it has to be either a closed thermostat or failed water pump.

I'm not meaning to take the thread off topic. If my cat is also bad then I will likely try this cleaning method
  Reply With Quote
Old 08-23-2019, 05:33 AM   #75 (permalink)
Not Doug
 
Xist's Avatar
 
Join Date: Jun 2012
Location: Show Low, AZ
Posts: 8,178

Chorizo - '00 Honda Civic HX, baby! :D
90 day: 35.35 mpg (US)

Mid-Life Crisis Fighter - '99 Honda Accord LX
90 day: 36.52 mpg (US)

Mom's grandmamobile - '06 Toyota Camry SE
Thanks: 5,292
Thanked 1,521 Times in 1,156 Posts
Who replaced the head gasket? If it was someone like me, I would not feel terribly surprised if it failed 20,000 miles later. If the engine is now burning coolant and\or or oil I could see that damaging the CC and the unit itself can become damaged if it overheats.

However, this guy's Chrysler's engine blew the gasket when the cat clogged: https://mechanics.stackexchange.com/...he-cat-to-plug
  Reply With Quote
Old 08-23-2019, 10:16 AM   #76 (permalink)
Master EcoModder
 
Join Date: Aug 2018
Location: USA
Posts: 288

Jeep - '97 Jeep Cherokee Sport
90 day: 19.36 mpg (US)
Thanks: 76
Thanked 48 Times in 46 Posts
A shop that I trust did the job. However, the car in question is a subaru...
A clogged cat would be easy enough to diagnose once I get the car on jack stands.
I really hope the code is just because of a dirty air filter or something...
  Reply With Quote
Old 08-23-2019, 10:50 AM   #77 (permalink)
Not Doug
 
Xist's Avatar
 
Join Date: Jun 2012
Location: Show Low, AZ
Posts: 8,178

Chorizo - '00 Honda Civic HX, baby! :D
90 day: 35.35 mpg (US)

Mid-Life Crisis Fighter - '99 Honda Accord LX
90 day: 36.52 mpg (US)

Mom's grandmamobile - '06 Toyota Camry SE
Thanks: 5,292
Thanked 1,521 Times in 1,156 Posts
A mechanic told me they stopped replacing Subaru head gaskets because they kept coming back.

I just do not see a shop refusing a $1,750 job with approximately a 0% chance of failing during their 12-month, 12,000-mile warranty.
  Reply With Quote
Old 08-23-2019, 11:02 AM   #78 (permalink)
EV convert
 
oil pan 4's Avatar
 
Join Date: Jul 2011
Location: NewMexico (USA)
Posts: 7,745

Sub - '84 Chevy Diesel Suburban C10
SUV
90 day: 19.5 mpg (US)

camaro - '85 Chevy Camaro Z28

Riot - '03 Kia Rio POS
Team Hyundai
90 day: 30.21 mpg (US)

Bug - '01 VW Beetle GLSturbo
90 day: 26.43 mpg (US)

Sub2500 - '86 GMC Suburban C2500
90 day: 11.95 mpg (US)

Snow flake - '11 Nissan Leaf SL
SUV
90 day: 124.63 mpg (US)
Thanks: 178
Thanked 2,443 Times in 1,903 Posts
Exhaust blockage can burn exhaust valves, blow head gaskets and crack a head. It's bad.
__________________
1984 chevy suburban, custom made 6.5L diesel turbocharged with a Garrett T76 and Holset HE351VE, 22:1 compression 13psi of intercooled boost.
1989 firebird mostly stock. Aside from the 6-speed manual trans, corvette gen 5 front brakes, 1LE drive shaft, 4th Gen disc brake fbody rear end.
2011 leaf SL, white, portable 240v CHAdeMO, trailer hitch, new batt as of 2014.
  Reply With Quote
The Following User Says Thank You to oil pan 4 For This Useful Post:
Xist (08-23-2019)
Old 08-23-2019, 08:46 PM   #79 (permalink)
Cyborg ECU
 
California98Civic's Avatar
 
Join Date: Mar 2011
Location: Coastal Southern California
Posts: 5,219

Black and Green - '98 Honda Civic DX Coupe
Team Honda
90 day: 64.33 mpg (US)

Black and Red - '00 Nashbar Custom built eBike
90 day: 3671.43 mpg (US)
Thanks: 1,859
Thanked 1,555 Times in 1,058 Posts
Quote:
Originally Posted by Taylor95 View Post
A shop that I trust did the job. However, the car in question is a subaru...
A clogged cat would be easy enough to diagnose once I get the car on jack stands.
I really hope the code is just because of a dirty air filter or something...
For what it is worth, my CAT is still running strong after the cleaning. I have twice seen isolated returns of the P0420 CEL. They were months apart. Both were on long trips on a hot day. The second event was during a high mountain climb into the high desert of SoCal, under significant load fir a long duration. Each time, clearing the code with my ultra gauge did not produce a recurrence. I think this indicates that the clean is good, but the CAT does not become "new" as a result.

__________________


See my car's mod & maintenance thread and my electric bicycle's thread for ongoing projects. I will rebuild Black and Green over decades as parts die, until it becomes a different car of roughly the same shape and color. My minimum fuel economy goal is 55 mpg while averaging posted speed limits. I generally top 60 mpg. See also my Honda manual transmission specs thread.

  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com