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Exhaust leak, struggling to get up to speed


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Hi all,

I have a 2002 forester, on the way home tonight (highway) all of the sudden the car got very loud. When I got off the highway, from a stop trying to accelerate the car was really struggling.

 

Rpm seemed fine

No engine or other warning lights

Idle is very smooth

Gets louder the more gas you give it

 

When I got out of the car it sounded like the noise was directly under the front door.

 

In the past there was a code for the cat but engine light cleared and hasn't come back (about 6 months ago)

 

Any suggestions or ideas?

 

Thanks,

Denise

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The car has 220k (13670 miles) Has always been well maintained, oil changes very regularly. Coolant flush, transmission flush all within oem required time frame.

 

I am the 3rd owner but have all the repair history (has been going to the same mechanic since new) .

 

Only repairs it has ever needed are pretty much all maintenance.

Brakes, wheel bearing, timing belt etc.

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I'm not sure how reliant EJ22 and EJ25 are on exhaust backpressure as I've yet to try and drive mine with an unbolted pipe, but some engines really need it. Without the backpressure, the engine can loose a bunch of early rpm torque and requires a heavier foot on the throttle to get it moving. MPG will also tank. 

 

It's quite possible the exhaust just separated at a flange, and the extra loud noise is giving the false impression you are going faster than you really are. Also possible your cat was clogging and there was too much backpressure at the flange and it just gave up (rust being a driving factor).

 

Get an actual mechanic to inspect your cats for blockage while also determining where the hole or separation is at. Make SURE you explain to them you only want an inspection.

 

If cats are OK, and pipe just needs welded back, see if they are able. If you go to a Midas or similar "muffler" shop, they will most definitely say "the entire pipe is shot, it must be replaced" then they'll try and sell you an ultra expensive "cheapo" Y-pipe with cats, which is dishonest.

 

A "custom muffler" shop (if you have one locally) are the places that will actually FIX the pipe with a $50 weld job and you'll be on your way.

 

IF mechanic states cats are bad, ask them to SHOW you. The substrate ceramic inside a cat looks like a screen on your house windows, only instead of being 1/32" thick, the cat can be 8-10" thick, but you can still see all the little screen holes- WHEN the cat is OK. Should be able to see right through it.

 

When they fail, they tend to melt like raw glass and will look like a giant blob of taffy. Often, only part of the cat fails, allowing leaving some of the "screen" holes intact, but a giant blob beside them.

 

IF your cat failed, you'll need the mechanic to explain WHY it failed. Chances are, the CEL you ignored was more important than you gave it credit. I think overly lean conditions can result in overheated cats. 

 

Also, if you get the cats replaced, ASK FOR YOUR OLD ONES! You can get roughly $75 for them at a junk yard, or possibly more from an actual core place (the place the junk yard sells their cats to). If you just let the mechanic or whomever take them, they'll make money off them, and NO, they won't tell you this. They'll act like they are doing you a favor.

 

As LuckyTexan stated, a vacuum gauge can help diagnose a clogged cat if they are clogged, and you can google sites that cover where a healthy engine should be on the vacuum gauge, as well as how steady the gauge should be.

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Like I said above, a "custom muffler shop" will almost always fix a broken section. I think our cars have a common failure after the last cat, as many seem to bust the weld and the pipe pulls out of the casing. THAT can be fixed fairly easy by any competent welder, and often runs $35-55 for them weld back and maybe takes 15 minutes. I've gone this route on my personal vehicles for last 10 years and always love saving hundreds of dollars.

 

A "Midas" or similar chain muffler shop, almost exclusively push pre-made sections and charge $300 and up to replace, but they'll stick in cheap piping that can rot out in several years. 

 

EX: I had a Lincoln Mark VIII with dual mufflers. Bought some better flowing Summit Racing mufflers and went to a muffler chain years ago, asked what it'd cost to put newer mufflers on. Guy looked me dead in the eyes and stated "those aren't factory, they won't work". He went on to say they weren't the same size, but he could get factory replacements for me instead. Needless to say, this was utter rubbish as the mufflers were eventually installed and were still on the car when it was sold.

 

The factory piping is better steel and it often behooves you to patch it up as it'll probably still outlast the replacement.

 

If the actual flange busted out, they make repair kits that have a new flange that clamps to the pipe, then fits right up like the stock part.

 

Post some pics and you'll have a better idea of what it'll cost and how severe it is.

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Working on posting pics, for some reason they will not upload...

I don't know enough about cars so it is hard to describe... It is broken right after a larger piece that is just before the drivers door. Then the pipe goes on to another larger almost pill capsule shaped piece... As soon as I can get pics up I will. Thanks for the help!

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As looking at the pic, on the left, the larger round thing is the cat. On the right, the silver-colored long appears to be a resonator (they typically smooth out some noise in the exhaust).

 

It looks like the pipe attached to the resonator rotted, and appears to be aftermarket (remember when I said muffler chains push "cheapo" piping? All that rust is o a cheaper pipe).

 

Look online for your city and google "custom muffler shop" and see what appears. If you have to travel 20 miles, it'll be worth it. My go-to place is roughly 20 miles.

 

Call them and say "My pipe rotted AFTER the last cat flange, and I'll need to have a small section of pipe welded in. CAN YOU make the type of repair?"

 

They'll most likely say yes, but need to see it before committing to a price. If they say they need to remove the resonator (unlikely) it won't really matter, but the pipe that resonator is attached looks heavily rusted near the back, and might as well replace the section with a straight pipe, or whatever you are comfortable with.

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Just make sure the pipe to the right of the hole (as seen from pic perspective) with silver resonator won't fall and drag on the ground. If it dropped and hit a hole in the pavement, it could potentially break and puncture the floor of the car.

 

I bungee cord or metal coat hanger can hold the rear section enough to avoid a $100 tow bill. Just attach around pipe and twist ends into something firm on the body. Since it's pretty well broken, the rear pipe shouldn't get to hot, allowing a bungee cord to hold it, otherwise a metal coat hanger works great.

 

Considering the break is under the passenger area, leave your vents off and keep windows down so fresh air is cycling through the cabin. Wouldn't drive anymore than needed to get it fixed, just due to the possible fumes, but with windows down and avoiding them up while stopped. 

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Cat is probably OK. If you take a flashlight and shine it into the hole, you should see a white colored "screen", just like your screen door or windows. If it looks like a screen, it's probably OK. If there is a blob of taffy protruding instead, or an entire section missing i.e.a big hole, then it's bad, and some cats are dual or triple layered, meaning they have 1, 2, or 3 "screen bricks" stacked in the casing, with a small gap between them. It's possible the front stack can be damaged, with others OK.

 

If the car wasn't down on power BEFORE the hole occurred, chances are the cat is OK. As mentioned earlier, the loss of exhaust backpressure, coupled with the excess noise, could make the car feel slower vs. how loud it is, as well as actually loosing low RPM torque, which would make the car not pull as well. Some cars are sensitive enough that even removing the muffler and running a straight pipe instead, can drop low RPM torque and tank MPG (might sound cool until you get tired of it).

 

I remember a friend had an early 90's Bonneville with the bigger V6 and his pipe dropped right after the cat, and it lost a ton of power. My other friend somehow got the idea to stick a sock over the opening and the back pressure that sock created actually restored power, albeit briefly until it burnt a hole ;) (this was back in high school mind you)

Edited by Bushwick
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Have an appointment this afternoon with a local exhaust shop elite stainless steel. Just you said he thinks just a small piece or pipe welded in should do at the cat. He will look at the second spot after the reasonator and see what can be done there as well. Tried to look into the cat for any signs of damage, but to such luck.

Will keep you posted on any updates, I am sure they will mention if there is any cat damage.

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Good to hear you found a shop willing to do actual repairs. Here in the US, you wouldn't believe how difficult that can be as so many places just outright refuse to either weld anything, reset air bag lights, etc. that when you do finally find a shop willing to go the extra mile and not soak you with up-selling lower-priced junk to avoid an actual repair, etc. it's such a relief. 

 

 

Wait and see how it runs after the repair. If it feels like it did before the pipe failure (dunno if the ECM needs reset [disconnect neg- battery terminal for a few moments to clear it] in case it's overly sensitive, or not) or really close, and isn't struggling anymore, you are probably OK.

 

It might take a couple days of driving if it tried to adapt to sudden decrease in back pressure. Not really sure how involved their ECM's monitoring is to be honest. 

 

If it feels way down on power still, even after a day of running, a $15 vacuum gauge "T" into an engine vacuum line, then with engine idling and warmed up, it'll tell you right away if any cats are clogged, as well as basic running health of engine. A blockage in a cat for example will decrease vacuum.

 

Here's a couple helpful links: (1st link covers testing to eliminate clogged cats or collapsed mufflers) i.e. excessive backpressure;

http://www.gregsengine.com/using-a-vacuum-gauge.html

 

http://www.tuneruniversity.com/blog/2011/05/check-your-engines-health-with-a-vacuum-gauge/

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Update

 

The pipe is horribly rusted (he showed me) in a few locations and there is a leak at the hanger.

 

He considered putting a piece of pipe into the cat flange (I think) and then into the rusted out pipe where he could get a good spot. He said it may hold out for a couple weeks.

 

He priced a cheap pipe and flange assembly with gaskets (about 200.00) and he said about 45mins labour. Stainless steel option was about 275.

 

I asked him about running a straight pipe and bypassing the resonator (as mentioned earlier in this post) He said he could do stainless steel that way for about 200.00, but I may hear some louder exhaust noise at high RPM's.

Decided to go the straight pipe in stainless, will see how that goes... Seemed better than another crap pipe and if I can't stand the sound (doubtful, that is what the radio is for!) then when I have a little extra cash I can always switch it back out for a stainless steel with resonator.

 

As for the cat, he showed it to me, said at least on visual inspection it looks great, although there are 2 cats and he can not see the first one without cutting into the pipe.

 

Thanks so much for all of the advise, through the years everyone has always been super helpful.

 

Denise

1995 Subaru Impreza

2001 Subaru Forester

2002 Subaru Forester

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Glad to hear it worked out and is back up and running. Stainless will probably outlast the car ;)

 

 

In my experience, resonators typically smooth out a droning increase that's often present around 2500 rpm in Ford V8 cars (been awhile, pretty sure it's 2500 or very close to that). Basically, if cruising and the engine is holding that RPM, it can sound a tad louder to very loud depending on how quiet the factory mufflers and sound deadening are. IIRC, 2500 would be the "peak" where it'd be quieter at 1500, then gradually peak at 2500, then mellow out above 2500, when running a freer-flowing muffler. On smaller engines, it may or may not be noticeable. Either way, you'll save $$ not replacing it, and that's just one less area to fail.

Edited by Bushwick
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  • 6 months later...

I had my exhaust replaced from Header down and I only put 1 Cat on with 0 resonators and a high flow muffler. My CEL stays on and there is a lack of power as well as god awful drone. Does the EJ22 require 2 cats? Do resonators create back pressure? I am finally getting close to having the money to get it fixed, but I want to know what to get so it is right this time. Please help me....

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