I think my catalytic converter is going out the window...

[TridenT]

So, it seems like my cat is melting again. I got a new cat in Dec 2012. My previous one melted completely and was causing exhaust to fly out before the cat and poor acceleration and so forth.

Guess what's happening now? Poor acceleration and some hesitation. All my oil was gone when I went to do an oil change. (No visible oil loss in the first 1k-2k of miles. Dipstick dry in the past 3-4k.)

I'm thinking my catalytic converter is melting again. And the worst part? I'm on the road again... So, I cannot change it out myself or drop the exhaust and run the car to see if that is really the issue or not... :'(

Anyway to test whether or not the catalytic converter is completely gone? I have a check engine light that I will check again but the code hasn't been P0420 (like last time), it's a P0141 (or 0142, I forget) which is about the O2 sensor heater malfunctioning. (A wiring issue, as far as I have tested... I've replaced the O2 sensor. Still happening. It seems like it's not getting current or something. I recently replaced the carpet in my car and so one of the wires may be cut/damaged.)

I've been driving with that CEL for the past 4 months without much issue until now. It's been the same code for all the time. Gas mileage has been fine and so has performance.

So--... what else could cause poor acceleration and bits of hesitation? I have a 2000 honda civic ex.

 

[phucheneh]

Cats don't melt on their own. Your engine was already running like trash and wasn't fixed when the cat was replaced.

How many miles? Ever replaced the plugs? Cap/rotor? Adjusted valves?

That plus the timing belt (and oil changes) is pretty much all your engine needs to run forever.

 

[TridenT]

I think the car is probably running rich and causing the cat to melt. A lack of the secondary O2 sensor reading might be a cause of that...

I've replaced the plugs multiple times. I haven't adjusted the valves or replaced the cap/rotor. I've considered adjusting the valves but I didn't. (I don't own the feelers for it)

Car is now at 176k. Last time I changed out the cat was probably around 150k.

Also, the car burning oil might be a cause too. (Bad piston rings?)

 

[jlee]

I think the car is probably running rich and causing the cat to melt. A lack of the secondary O2 sensor reading might be a cause of that...

I've replaced the plugs multiple times. I haven't adjusted the valves or replaced the cap/rotor. I've considered adjusting the valves but I didn't. (I don't own the feelers for it)

Car is now at 176k. Last time I changed out the cat was probably around 150k.

Also, the car burning oil might be a cause too. (Bad piston rings?)

A set of feeler gauges is $5-6..just fyi..

 

[TridenT]

A set of feeler gauges is $5-6..just fyi..

I'm aware but you know. Time and money on that shit adds up. One thing here and another there, etc.

I wouldn't have been able to keep them either. I only have a few tools right now. I'm going to go over to harbor freight and buy some shit now to do some simple testing. (Feelers included...)

 

[phucheneh]

If your engine is not just having outright ignition misfires, it is probably suffering from low compression due to valves hanging open. As the valves and seats wear, the valves recede into the head, raising the stem height and making them stay open during. If you do a compression test, I bet you will find multiple cylinders with low compression. Which causes crappy combustion and unburnt fuel (and excessive oxygen) in the exhaust. Lots of hydrocarbons + lots of free oxygen + catalyst = melted catalyst.

 

[TridenT]

Yeah, I guess need to test for engine compression. I have wanted to do that for some time but you know... buying all these tools takes money. If I have bad seals then I'll have poor compression. If I have bad valve clearance then I'll have poor compression. At least I can find out if it's those two or not.

I need to consider buying a cordless electric impact wrench with a couple spare batteries. I don't know where I could buy that for a reasonable price and one that could handle taking off lugnuts of a tire and working on an aging car exhaust. I hear IR makes a good one but I don't know if cordless electric is up to that job.

 

[Zenmervolt]

I'm aware but you know. Time and money on that shit adds up.

As you are learning, the cost of not fixing things adds up too.

Burning as much oil as you claim to be burning will definitely foul a catalytic converter. Simply replacing the cat will not solve the underlying issue and will just result in a third melted cat.

Frankly, this is probably related to the fact that you were driving around with the "check engine" light on for thousands of miles without even bothering to check the code. Or to the fact that you've admitted to letting the oil level drop to nearly 2 quarts low over the last several oil changes.

At this point, it's a small miracle the car's still running at all the way you've been treating it.

ZV

 

[TridenT]

As you are learning, the cost of not fixing things adds up too.

Burning as much oil as you claim to be burning will definitely foul a catalytic converter. Simply replacing the cat will not solve the underlying issue and will just result in a third melted cat.

Frankly, this is probably related to the fact that you were driving around with the "check engine" light on for thousands of miles without even bothering to check the code. Or to the fact that you've admitted to letting the oil level drop to nearly 2 quarts low over the last several oil changes.

At this point, it's a small miracle the car's still running at all the way you've been treating it.

ZV

She's a beast! I'm trying to resolve some of the issues though. A lot of these things having really been a problem until my catalytic converter has gone out. Which obviously is a serious issue. I never wanted to work on adjusting the valves because I was told it's more likely I'll fuck it up than get it right. But in hindsight, I should have just gotten the feelers and done a reading but even then... I'm still skeptical I'll be able to use those feelers correctly.

The code is still the P0141 btw. I was watching some metrics as well from the OBD2 reader while driving but I don't know how to interpret the readings. (When it's OK to see rich/lean in fuel sensor trim readings and by what %)

 

[phucheneh]

1) It's the downstream sensor, it does not affect fuel trim
2) It's a heater code.

You oil consumption could be a contributor to catalyst failure. Or well, it pretty much definitely IS, but the question was it the beginnings of said failure...I would wager that no, it's not, and simply getting your engine into better running order and fixing the restricted exhaust will do a lot to lessen blowby and oil consumption.

A proper tune-up at a decent shop would've cost less than the first converter.

 

[colorblind]

So, it seems like my cat is melting again. I got a new cat in Dec 2012. My previous one melted completely and was causing exhaust to fly out before the cat and poor acceleration and so forth.

Guess what's happening now? Poor acceleration and some hesitation. All my oil was gone when I went to do an oil change. (No visible oil loss in the first 1k-2k of miles. Dipstick dry in the past 3-4k.)

I'm thinking my catalytic converter is melting again. And the worst part? I'm on the road again... So, I cannot change it out myself or drop the exhaust and run the car to see if that is really the issue or not... :'(

Anyway to test whether or not the catalytic converter is completely gone? I have a check engine light that I will check again but the code hasn't been P0420 (like last time), it's a P0141 (or 0142, I forget) which is about the O2 sensor heater malfunctioning. (A wiring issue, as far as I have tested... I've replaced the O2 sensor. Still happening. It seems like it's not getting current or something. I recently replaced the carpet in my car and so one of the wires may be cut/damaged.)

I've been driving with that CEL for the past 4 months without much issue until now. It's been the same code for all the time. Gas mileage has been fine and so has performance.

So--... what else could cause poor acceleration and bits of hesitation? I have a 2000 honda civic ex.

The code you have is for the rear oxygen sensor. Have you replaced this sensor? Also do a Google search for Honda TSB 99-029. This TSB is for a common wiring issue these have though normally you will have additional codes stored and a failed fuse. Hope this helps.

 

[DaTT]

I melted a cat once. Drove around for 2 years with a stuck lifter on my Audi 4000, then let it idle for around 10 hours while we camped and listened to music. Was a long drive home as the car had a top speed of 30 KM/h the next day. I got home at night and there was a bright red glow from under my car....cat was red hot.

Next day I got a new cat and the lifter fixed....oh the high school days.

 

[RLGL]

Time to junk that one

 

[TridenT]

I'm going to do some tests today. Compression test mainly. I got the oil last night for the wet test. (Also need it to top off the car if it sucks down oil anyway)

But if my car is burning oil then wouldn't that indicate bad piston rings? It could have bad valves too but shouldn't the burning of oil just be from bad rings or a leak somewhere else? (Just gonna go with rings at this point, just as a start, even though there could be a leak or whatever)

I actually was about to do the compression test and then I remembered that 5/8 spark plug sockets don't come off very easily while the spark plug is screwed in. And then I went to look for a 5/8 socket and was like, "oh wait. I don't have sae sockets with me..." This was after I had already taken one plug out. (I was having a very much, "fuck it. I'll just use a metric that is close enough." moment.) and then I got one of my sockets (had a 15 and 17 but no 16...) and saw that the 17 was too large to fit in the spark plug tube.

At that point I was like, "aww hell no mother fucker!!!!" (I also locked myself out of my car last night and had to pay a locksmith $65 to get them out... Many others things are going on too... This is the nicest problem of all things.)

But I had oil. And I was like, "dat rubber is shitty and super sticky. Oil!!!" So I dipped the socket in oil, removed as much excess as I could, and then put it on the spark plug (taken out of the engine) and then wiped off the excess on the plug and did that about four times. (Very little oil was getting on the plug. Very very little.) Screwed the socket back in and then wiped it off while in the tube as best as I could. No misfires as far as I can tell.

I'll get a regular deep 5/8 socket today...

 

[TridenT]

Also, junking my car at the moment is very difficult. I'm on a road trip trying to find a place to live and I don't have a whole lot of dough to throw around...

Otherwise I would just buy a used toyota prius or something of that sort.

If this car fails beyond reasonable repair, I might have to just find another used civic since I don't have a ton of money to toss in the air.

 

[sontakke]

You have no money to fix the car but you want to buy cordless impact gun with few batteries so can take the wheels off? You sure have your priorities right!!

 

[TridenT]

You have no money to fix the car but you want to buy cordless impact gun with few batteries so can take the wheels off? You sure have your priorities right!!

It's something I am likely to buy anyway and have a use for in the future. I was only considering it. It's pretty expensive to buy in store.

Throwing money into this car hasn't proven to be a super wise investment. (I've already spent over $1000 recently repairing a lot of damage done to it by thieves.)

I'm going to try to do the compression test. I would measure the valve clearance but I don't have a way to rotate the crank since I need to have the car jacked up to do that with any accuracy...

Ugh. It is looking like I would have to take it to a shop to do some of this work. (Replace cat, adjust valves) If the rings are bad (shown by the wet test giving significant improvement in compression, correct?) then I'm in a world of hurt...

 

[TridenT]

I'm thinking:
If rings are bad, cost is $400 for cat ($260 for cat, get fisted on labor and gaskets for $140), plus $700+ for ridiculous amounts of labor to replace rings (almost cheaper, maybe cheaper, to just swap engines...).

If rings aren't bad then it's $400 from before but now $100 for valve adjustment.(even though it too is an easy job, I will get fisted)

I'm thinking if the rings are bad then I need to dump the car or drive it over to Phoenix from denver and pray I make it.

 

[TridenT]

Test done for compression:
Cylinder 1,2,3,4
Dry 135,135,129,149
Dry 140,130,135,142
Wet 175,155,210,185
Wet 190,185,195,190
Wet na,na,180,na

My method for dry:
Remove all spark plugs and wires. Screw in hose for each cylinder and attach to gauge. Hold the gas all the way down (supposedly this is supposed to stop gas flow). Turn key to start car and let the engine crank over 5-7 times.

My method for wet:
Same but add about 1/2 to 2/3 the amount the 5 qt Mobil 1 cap holds to the cylinder before testing. Add once, test, unplug the gauge (it doesn't let the pressure out with oil in the cylinder unless you unplug it from the hose), and then test again. (No addition of oil)


I might have added too much oil but if don't have a tube to stick down into the spark plug tube and into the cylinder to add oil directly. I used a smaller sized funnel one would use to fill their oil to get it near the bottom of the tube.


I don't know what a healthy amount for my engine is in terms of psi but the dramatic difference between wet and dry is cause for alarm. As well is the lack of similar readings for all cylinders.

It seems that 190 is about the correct number for a wet run though... Or at least, it's common in my case.

 

[Squeetard]

Cats don't melt on their own. Your engine was already running like trash and wasn't fixed when the cat was replaced.

I think the car is probably running rich and causing the cat to melt. A lack of the secondary O2 sensor reading might be a cause of that...

This. When an O2 sensor is in error, your car runs in "open loop" or Limp mode. Basically it ignores the sensors and runs on a preset fuel map that is on the rich side for safety. This is bad for the cats and your fuel mileage.

 

[BUTCH1]

She's a beast! I'm trying to resolve some of the issues though. A lot of these things having really been a problem until my catalytic converter has gone out. Which obviously is a serious issue. I never wanted to work on adjusting the valves because I was told it's more likely I'll fuck it up than get it right. But in hindsight, I should have just gotten the feelers and done a reading but even then... I'm still skeptical I'll be able to use those feelers correctly.

The code is still the P0141 btw. I was watching some metrics as well from the OBD2 reader while driving but I don't know how to interpret the readings. (When it's OK to see rich/lean in fuel sensor trim readings and by what %)

She's a sick beast, burning that much oil means rebuild time, sometimes valve guides can leak some but not like the amount your going through, sounds like the rings are just shot, time for a tear-down or a junkyard engine.

 

[TridenT]

She's a sick beast, burning that much oil means rebuild time, sometimes valve guides can leak some but not like the amount your going through, sounds like the rings are just shot, time for a tear-down or a junkyard engine.

Yeah. Well, I want to tear it down. I've wanted to do it for a long time but I haven't had a garage in my own place for a while. My next place will.

I'm thinking of buying a jack and jack stands($200). Getting some penetrating oil, new gaskets, and new bolts. And then taking the cat off (with magic, because I don't think I'll get it off even with a 2ft breaker bar) and checking the status of it. If it has any melted grid in it, I can assume it's shot and is actually the issue of hesitation and acceleration. If it looks crystal clear and all honeycomb juicy then... What would you think it is then? Also, should I just punch a whole through the catalytic converter until I can replace it and the engine? I know the ethics and laws of such a thing are tenuous for me at best... But I'm not really having a whole lot of options here besides spend $1000+ to replace the engine and cat by someone else.

 

[PottedMeat]

Frankly, this is probably related to the fact that you were driving around with the "check engine" light on for thousands of miles without even bothering to check the code. Or to the fact that you've admitted to letting the oil level drop to nearly 2 quarts low over the last several oil changes.

drive it to ohio and dump it at ericthecarguy's shop. tell him he can make some videos on not throwing parts at cars, why people should care about their check engine light and oil levels, and maybe a etcg video on pity and pricing :twisted:

 

[jlee]

I'm aware but you know. Time and money on that shit adds up. One thing here and another there, etc.

I wouldn't have been able to keep them either. I only have a few tools right now. I'm going to go over to harbor freight and buy some shit now to do some simple testing. (Feelers included...)

Point is if you're going to say you didn't do it because you don't have the tool, and the tool is $5, that isn't the reason.

If you legitimately do not have $5 to buy a set of feeler gauges, PM me your address.

 

[Zodiark1593]

drive it to ohio and dump it at ericthecarguy's shop. tell him he can make some videos on not throwing parts at cars, why people should care about their check engine light and oil levels, and maybe a etcg video on pity and pricing :twisted:

Some dummy that called himself a mechanic said the check engine light doesn't matter (usually just for emission stuff), but even if is just a sensor, I am quite paranoid whenever I see that light. This thread is definitely a good reason for that.