MaxPayne79

Hey guys,

Firstly... AMAZING FORUM!!!
Been (quietly) coming here for the length of my 09 civic dxg. Forums in general are slowly dying off imo so it's wonderful to see this one still thriving and so damn big!

Anyway... Like i said i have an 09 civic with 239k on it. manual. I live in Toronto Canada but lived in LA for two years with the car (sometimes in the car) and that's where most of the miles came from (also drove there and back). Plus i drove to NY from Toronto 2x and to Chicago from Toronto 2x many years ago. Never had a problem except for the front calipers which needed to be replaced late last year. Otherwise, Not a single issue... until now. Not surprisingly lol.

The only mod i made is that while in LA i ripped off the Resonator by accident. Long story. And i found a hole in the clamp / gasket between the muffler and the cat subsequently replacing the muffler.

So what's happening now is that when it's either hot outside so 20*C + or when i drive the car around for more that 4 hours (uber), i lose horse power in the engine. And torgue. Engine gets very sloppy. My shifting is all off because I have to give the car more gas than normally to shift properly. Normally I shift at 2200 but once this "drop off" happens I have to shift at 2500, 2600. And the engine gets much louder as well.

When it comes to idle: While in stop and go traffic and the car is been driven for a few hours the rpm's drop to 650, 600 from the usual 750 and the car feels like it's going to stall because the engine twitches. And jerks. And like jabs. It's very unconformable fellas. And i feel every single twitch and jab and there seems to be no pattern to them. They're not violent but powerful enough for me to notice them and become concerned.

Also, once i ripped off the resonator I noticed right away that my engine became lazier and i have much more low-end torgue which ive never had in this car. Not sure if the low rpm's have anything to do with the resonator missing.

Please let me know what ya'll think.

ezone

Check engine light on? Got fault codes?

MaxPayne79

nope. nothing.

ezone

What happens if you shut the engine off and restart it--- Does it clear up and run ok for a while? Got more details?

Checked coolant level in the radiator? Both radiator fans run? Oil level? Air filter? Exhaust backpressure?


I haven't thought of something that would fit the (4 hour/heat) scenario yet....and I hate to just fire the parts cannon.

Got a scanner (or app) that can let you read live engine operating data? I like to be able to see ECM data while the problem is happening.
I'd like to be able to see how the AF and O2 sensors respond to heavy load while it acts up, and see what fuel trims are doing both ST and LT.

MaxPayne79

1) when i shut it off and let it cool down for a bit then it fixes the problem but for a very short time.

2) Coolant levels? haven't checked that but my temp gauge on my dash doesn't move. It's always just under the halfway mark. both fans run fine, oil is at 70%, air filter was bought in Nov BUT the air filter box wasn't sealed properly til about a week ago. i didn't notice that i didn't close it right tight. Don't know what the exhaust backpressure is. When i googled it, it said that it's a myth. ?

3) no scanner, no apps. Took it to honda and they ran in for codes and came out with nothing. at least they told me they ran it. quote is "if there was a problem it would 'throw codes'."

I'd like to figure out the rest myself but I don't know how to go about it. Is there a scanner that i can buy that shows me all of that information?

ezone

I meant restart without waiting for it to cool. Like 15 seconds then restart.
But you say it happens again very soon so I imagine just as soon as it heats up again?

Check the levels of both engine oil and the radiator (not just the plastic reservoir).

Possible a contaminated MAF sensor (dirt, bug, leaf) can screw with density measurement and therefore alter fuel injection calculations in a dramatic way, but I'd think this would be a constant problem- both cool and hot.

Backpressure refers to a flow restriction in the exhaust.

A plugged exhaust pipe (squashed or damaged exhaust pipe, restricted catalytic converter or similar) creates backpressure that the engine has to work against.

Picture trying to exhale through a coffee stir-straw....you might be able to do it slowly but you aren't going to run a marathon trying to breathe through it.Not all problems cause fault codes.
No-code diagnosis can separate the amateur parts throwing flush jockey from the professional technician.

Personally, I like this sort of challenge (as long as someone is willing to pay)


That takes experience, and a willingness to learn LOL
Good service information helps, and good tooling.

Depends. You can buy all sorts of scanning equipment....some are better than others, and of course the cheap ones usually don't give as much info as more expensive units. The more you spend the more you get.
Most will deliver at least a set of generic (basic) parameters that might help.....and at the top end there's the dealer level equipment.
The cheapest is probably a torque app (google it)for a smartphone along with the dongle that plugs into the diagnostic port.

Of course, reading and interpreting scanner data is kind of a black art, it takes experience to sift out good data from bad.

MaxPayne79

the car's performance kept degrading to the point that i HAD to take it in. Took it to my dads mechanic and not honda. After him and i spent about an hour driving around, he deduced that on top of the fact that the car is misfiring my exhaust may be plugged. Or the front end cat is clogged. We sat there revving the car at 2000 rpm and the engine just violently twitched. It was weird man, i've never seen anything like it.

He ran it for codes and sure enough, it told him that cycinder #4 is misfiring which is what the engine twitching in idle is all about. Also the coil may be damaged because the machine told him that nature of the problem is electrical and if it is a coil, then it may explain my low idle rpm.

So he's changing out all 4 plugs with iridium spark plugs, the one coil and cleaning the throttle body then resetting the computer.

Does that sound accurate?

ezone

Pretty much.

Did you ever actually check for fault codes, or did you just assume since you didn't see the light there were no codes?

Was the check engine light on when your mechanic drove it? If it had a 'dead hole' misfire, it should have also had the check engine light flashing angrily for the duration of the miss event.
That is, if the light worked correctly. (I've seen where people disable the warning light because they can't actually fix a problem)


I would have just swapped the suspect bad coil to another cylinder and then see that the fault code moves to the cylinder with the suspect coil...that can verify the coil is the problem... Spark plug set replacement I suppose is for regular maintenance...


If it's been driven long enough with a misfire, that can and will cause severe damage to the catalytic converter, which is where the low RPM limit and my suspected backpressure comment comes in....the damaged cat either breaks the substrate apart and clogs the exhaust, or the substrate melts and clogs the cat, or carbon and soot buildup clogs the cat.
The clog causes the drastically lowered RPM limit and low power when attempting to accelerate.

So....
fix the misfire problem first (assuming that is the root cause) hopefully it's just the coil and a set of plugs,
then fix the damaged cat issues if that's the collateral damage.

MaxPayne79

you know your stuff mate.

regarding the Cat he also mentioned the phrase 'melted cat' but he suspected that it may not be melted and the damage may not be that great because this only began happening two weeks or so ago and every time it happened, i'd go home. Remember, this only showed when it was warm outside (which is hasn't been) or after many hours of driving which which i did, but then went home. We'll see once the work is done on the car.

Regarding the check engine light: it never came one. Not once. Never flashed either. He asked about that as well. My check engine light has never come on during a car ride. Only during start up naturally.

the front cat has two sensors on it, wouldn't they come on if even the slightest problem would occur?
And the car passed smog about 4 months ago.

And about the codes, when i spoke to honda and told then to scan it for codes, they told me that if there was a problem then the car would show codes. I thought that meant that the code would flash on the dash lol. Or at the least the check engine light would come up with the appropriate code. Only god knows how long that code's been sitting there but my rpm's only began dropping a few weeks ago if that.

ezone

As I said earlier, this is not always true.
There are plenty of problems that do not cause codes to set. Not all problems can be detected by a computer, and sometimes engineers could not possibly predict every possible failure that could ever occur. Sometimes a problem doesn't happen frequently enough to make the computer decide it's a real problem.
Sometimes a fault code for one sensor can be caused by a completely different sensor.
Some faults and codes are not caused by sensors at all.

Not unless there is a failure that fits within the programmed parameters for testing of those particular sensors.

There is only one cat.
The two O2 sensors...(short version for the sake of brevity) one is used for fuel control, the other is for monitoring the condition/operation of the cat.

A physically damaged cat could physically damage one of the sensors. (breaks off the tip of the sensor)
BUT I'd expect a physically damaged sensor to generate a fault code, and yours has not done that. Yet.
If there's a (normal, non physical damage) sensor failure it could show up later on as well.

Also understand.... misfires can cause a cat failure, but as long as misfire code(s) are present in the ECM it will not perform self-testing of the cat.
As soon as the misfire problem is fixed and codes erased, the ECM may begin testing the cat during drive cycles ---and may later decide if it fails or passes, so don't be surprised if it fails and turns the CEL on a few days after you get it out of the shop.


You might ask the mechanic to make sure nobody hacked this.
Ask him to unplug an important sensor to cause a fault code that SHOULD turn on the CEL immediately, just to make sure the ECM is really able to turn it on in the event of a real fault code.

MaxPayne79

i'm about to get the civic back so we'll see what'll happen but I hope you're wrong about the cat. Tho i have a feeling you may not be but I hope you are. lol.

But thank you very much for taking the time to write up everything and dealing with my crap. Out of all the forums i posted this on, you're the only one who took This much time to help me out. Now i know what to look for in the future. Great learning curve here man.

Thank you!!

MaxPayne79

let me ask you something because i've noticed something crazy earlier tonight...

when my headlights are on, the rpm's during idle are higher then when the lights are off. does that make any sense to you? because i've never seen anything like it.

ezone

Yes....a slight RPM bump up with electric loads may be normal.

Might need to do an idle relearn as well. Disconnecting the battery and even erasing codes with some scanners can make the computer forget its learned idle values.

MaxPayne79

My mechanic said that he reset the comp but i'm not sure if he did an idle relearn.

could the alternator be going? or a weak battery?
on my way to honda dealership to test the battery.

ezone

That only means he erased codes.
Most people wouldn't even think to relearn idle unless there's a huge blatantly obvious problem with how it runs.

A slight change in idle RPM with electrical loads isn't unusual anyway, it has to compensate for loads by opening the electric throttle slightly wider (or IAC valve on older cars). Maybe you just never noticed it before the last disaster happened, now you're overly sensitive to every little nuance.
Does it crank at a normal cranking speed? If it's not dragging the starter it's probably fine.

Just do the relearn procedure yourself and see what happens.

MaxPayne79

Hey man,

When it comes the starting it sounds the same as it always has. cranks over twice then it starts. Doesn't seem slower.

Add yeah, i'm very paranoid right now lol.

When i turn on the AC i hear this swishing noise coming out the pipes in the top left corner of the engine (when looking at it) that i never heard before

Or I had him change the serpentine belt because it's never been changed, and now i hear a slight clunking noise coming out the engine soooo yeah, you could say i'm a little paranoid LOL.

ezone

Doesn't the AC cool well? Some noise is normal. Hiss noise comes from freon flow through the expansion valve which is in the dash, so you can hear it clearly when it makes noises.


The car probably made ALL these noises before it broke. You just didn't pay close attention because you could still put fuel in at the gas pump and the car would still pull itself down the road when you needed it to.

MaxPayne79

The AC cools well. For now. lol

MaxPayne79

So i did the idle relearn hopefully properly and haven't noticed any difference in the idle thus so far. It's still too low imo. 650-700 normal and 750 with headlights on. But something interesting happened during the process that I thought id share with you.

While I had my foot on the pedal @ 3000rpm's, when the fan kicked in, the rpm's spiked by about 100-200 to roughly 3200, stayed there during the course of the fan turned on, then came back down to 3000.

I thought maybe i did this with my foot so i waited to see if it'll do it again and sure enough fan kicked in and rpm's went up, fan turned off rpm's came came back down.

this is isn't normal right?

ezone

You will not change the base idle speed, it's all computer controlled there are no adjustments whatsoever.
Some minor fluctuation is normal as the computer compensates for loads, electrical and otherwise.
Sounds normal.

Before you continue thinking the car is somehow broken, let me ask you:
Is the original problem fixed?

Do you notice ANY of these things while driving it normally, and do they cause any problems with how the car drives down the road?

MaxPayne79

is the original problem fixed? no. The car still loses what seems like engine power after a while of driving around and the rpm's are still too low imo and I can still feel that strange engine twitching during idle what my mechanic and i thought were misfires in cylinder 4 but as it turns out...no.

After changing the coil, the sparks , the belt and the muffler the car feels more stable (and predictable) but still feels like it's just exhausted. lol. Like it doesn't wanna go on anymore. And the engine gets loud. That's another think i noticed that once it's been on a road for a while and i begin losing the power, at the same time as i rev the car up to 2500 rpm's and ****, the engine just gets loud. that's only way i can describe it. Much louder than before. And i had the battery tested at honda and it was "near perfect".

So i don't know bro... Maybe Sherlock Holmes can solve it.

Oonce i'll have more money, i'm going to take it into honda and have them go through it inside out. Either that or i'm selling this car while it's still drivable.

I mean look...It could still be the frond end Cat. As you said. OR, the car has an electrical problem somewhere. Currently i'm hunting down the Air intake resonator chamber to put back on the car. My mechanic is convinced that it's an airflow problem whereas i'm convinced that something is choking this car to death.

MaxPayne79

There are other things as well.

(long read)

When i went down to California from Toronto, i had all my liquids and fluids from Toronto. This car has gone through 8 summers and winters and was fine. So now i'm in LA and it's hotter than hell right? Then i ended up living for a while in the High Desert when it was like 120 every freaking day. Every DAY bro. My car baked out there, and i drove around in this ****. this is after the resonator was ripped off and it still seemed fine. No noticeable issues. I was amazed.

fast forward, i'm back in Toronto with my civic and we hit winter a month after i come back. First thing that happens: the original windshield wiper fluid freezes both in my reservoirs and in my trunk. this is nuts to me because this stuff is rated for +50 and -50 Celsius so how can it freeze? it was rock solid! never seen anything like it. So i'm thinking...what if other fluids in the car are losing their cohesion when i'm driving around and the car is heating up. Maybe the coolant isn't keep up. I know my A/C is making very strange noises in the High and Low pipes when it's on. again, another liquid that seems to have gone bad.

So i'm thinking that i'm going to replace all the fluids and see if it's any better.

Sorry about the essays today.

ezone

Bring it to me.
Exhaust (cat) can be tested for excessive backpressure and proven fairly easy, it's not a complicated process IMO.

How does it do when you rev far beyond 2500 RPM?

Full throttle acceleration from idle to redline fuel cutout, all the way throughout first and second gears....
Does it drop off power before redline or does it pull strong in a mostly linear fashion all the way up to the shift points (redline),on both shifts?

You've mentioned it has to be hot before the car loses power, yes? Do the above check long before it loses power, then repeat after it has been driven a long time and loses power.



I'd have a scanner on it during a test drive, recording some 'in-flight data' during the full throttle acceleration checks.... I'd be watching for AF and O2 sensor responses (clue about fuel delivery) along with MAF response and MAP responses while driving. And much much more. There's a lot of data available from the computer for someone who has the necessary equipment and can make use of it, interpreting that data could indicate a need for physical tests such as fuel pressure or backpressure.

A high end scanner is an invaluable tool in the hands of a master troubleshooter.
The same extremely capable scanner in the hands of a parts replacer is not much more than a code number reader...or a wheel chock.
Resonator...the one stuffed into the front fender, or something else?
Air filter box is not stock? MAF is the important sensor in the intake system. If you have a CAI it should be pretty damn easy to tell if that's clogged up. If filter box is still stock one could detach the inlet tube from the bottom of the filter housing to eliminate the chamber in the fender as a possible restriction problem.

Another thought: If the air inlet is in a location that has wide temperature variations, that can screw with the MAF (sudden air density change messes with fuel quantity calculations).

Winter in Toronto, just how cold was it there??
If the washer fluid was from a warm climate or summer, it could have been rated for summer use and mostly water. Even if winter fluid was dumped into the reservoir, it would have been diluted by the (mostly water) that was still in the reservoir.
Cheapo discount fluid might be inaccurately labeled too. I think our usual winter solution only says -20F, but I know concentrates are available that could make that freeze temp rating a bit lower.

Anyway, washer fluid is nothing to base the rest of the cars' fluids' performance on. Washer fluid is usually topped off with an oil change, so you may not ever know what was dumped in it at the last shop.

What about your usual periodic maintenance? Haven't you been keeping up with routine trans fluid and antifreeze services throughout the cars life?

Freon (AC refrigerant) does not 'go bad'. It might have lost some amount due to seepage over the last 8 years though, but as long as it cools good I probably wouldn't worry much about it.

MaxPayne79

I wish i could bring it to you but you live far from me. Like in another country lol

Interesting tests... I'll check that out.

yea it's the resonator stuffed into the engine. that big black box.
Air filter is stock and the hose from the air filer is hanging down into the engine somewhere.

A/C cools fine. In fact very well because I just changed the glove box filter after like 5 years lol. Had no idea it was there. It's like a new A/C that makes weird noises in the engine

Regarding servicing... more or less on time. Sometimes i'd go over the oil change about 2k kilometers but that didn't happen often. Otherwise the rest of the fluids were done as the A or B services indicated. Sometimes sooner in the case of transmission fluid.

Another development with the car. Last night after I typed up my report for you, I went to start the car and it made a crazy screeching noise. !st time ever. Cold start. I turned the key, it went once over, crazy screeching noise, then turned over twice and started. I git freaked out so i turned it off. Waited a few seconds and it did it again. All pretty quickly because the car starts quickly. Turned it off and did it one more time and it didn't do it again. I'm thinking that maybe the guys who put the belt on didn't do it right? Idk bro.

ezone

All of these cars make AC noises after the engine is shut off, and it can continue making noise for quite a while as pressures slowly equalize inside the system.

I'd have to hear it.

I know some of these can squeak the belt briefly upon startup after it's been raining, and it's been raining so much here the last few days I thought I would have to build an ark to get to work.


Note to self: Don't let the elephants watch the rabbits.