Muffler rusted out and hanging so I broke it off. Should I leave it this way?

[Ryland]

A missing muffler can improve your driving because you can hear the engine better and it gets really loud when you floor it so you tend to drive softer, back pressure is caused by blockage and poorly designed/over/under sized exhaust systems, proper sized exhaust uses scavenging to help pull exhaust out of the engine so removing it would be like removing your fly wheel to save weight, after all it is a big chunk of iron.
There are calculators out there for figuring out the ideal exhaust size if you do want to try to improve your mileage with whatever you install next, they use your engine displacement and speed that you want to run at.

[Frank Lee]

My suggestion would be to replace or repair the exhaust system as necessary.

I've done quite a bit of exhaust work myself, but then I don't hire out for anything except tire mounting and glued-in windshield replacement. Anyway, when you do it yourself it can be quite affordable. On the latest one I did, I bought a section of pipe at O'Reilly's for $7 and a clamp for 90 cents and did the requisite cutting and fitting and that was that. For the Coupe I found a really nice all-welded, mandrel-bent system (probably factory) at a scrapyard; only problem was they'd torched the converter off. I was able to get a freebie short pipe section at a repair shop and I welded it to the front of that nice factory system for a total cost of "free". That was many years ago and the system is still good.

You may be able to find a complete system, or at least a muffler, for cheap online. I'd suggest looking at Rock Auto . com.

[Fat Charlie]

Originally Posted by toc

Fix up the muffler with some pipe to route the gases back to the rear of the vehicle, if they enter the cabin they can be very dangerous for those inside the car.

Shouldn't take much more than some correctly sized pipe and a bit of welding, I would think (that is, without the muffler, but then if you 'fix' it, could be issues later when the car is inspected)?

+1

You have to be alive at the end of the tank for the mileage to count, and one ticket will cancel out any possible savings.

[larrybuck]

The main thing I'd be concerned about, is; does this setup cause the eng. to run too lean?

Are you overall driving WAY softer? Can you in your driving area actually gradually coast up to speed (very leisurely) instead of put it down acceleration 95% of the time or more? Many hills to contend with? Do you EVER hear it pinging?

I agree w the others, that at least you should extend your pipe further.

What about a freeflow resonator just before exhaust tip!

Last, but not least......trip to dollar store: women's makeup cotton puffs...100 for $1, you break each in half roughly, custom it to your ears, you can usually keep that pair looking clean for at least a week. Think of the value!!!

[Ryland]

Originally Posted by larrybuck

The main thing I'd be concerned about, is; does this setup cause the eng. to run too lean?

I would worry more about it running to rich, the reason that broken exhaust can bend valves is from the stall in exhaust flow from the lack of exhaust pipe, a cold draft of fresh air hitting the exhaust valves then cause them to warp and bend, if that draft of fresh air hits the o2 sensor it will see that fresh air as unburned and call for more gasoline to be used.
This is of course easy to check for by pulling the spark plugs and seeing if you are running rich or lean, so it might be an issue and it might not but either way you can check for your self and it will not cost you anything other then a few minutes of time.

[Frank Lee]

Sounds like the cat is still hanging on there so none of those things is likely to happen.

[Bdorion1]

This is why I like this site so much. All the ideas bouncing around are things I probably wouldn't think of on my own.

It did pass inspection only a week ago. I was curious if the guy at the shop would say anything about the missing muffler/ ecomods I've done but apparently he was too busy to ask, or had seen so many strange things on peoples cars he just didn't care. The "cat still hanging in there" was probably my saving grace as it allowed me to pass emissions. (That phrase conjures up images of a haggard feline clinging desperately to the underside of my car. Ha)

BTW the whole midpipe is shot. So were looking at a new exhaust system but the catalytic converter is still good. As much as I like DIY, I am a 21 year old still in college so the welding/ metalworking/ garage thing is beyond my current ability (unfortunately).

As for the lean/rich debate, besides the steady and gradual improvement in my mpg over time no noticeable changes have occurred. A lean or rich burn would affect this one way or the other no? I will check the plugs tomorrow and see if that gives me anymore useful info.

Now as to why I am such a cheap SOB. This car is 14 years old and 171K miles. I know this is a baby car to many of you, but it also has several significant problems. About 3 weeks ago I came out to see my coolant all over the street where I park. Some bar's stop leak did the trick (for now). Oil is leaking presumably into the engine because I never see any on the ground, but it keeps needing more oil. The time between each necessary top off is diminishing. The transmission is doing weird stuff. Hard shifts between gears mostly (autotragic tranny I'm sad to admit). It occasionally stalls inexplicably (only happened twice many months ago but still curious). Brake lines look like they have seen much better days, suspension as well. And to top it all off, the rear window is separated from the shrunken vinyl top. I've tried every way to repair I can think of but its currently held on by gorilla tape with carpet tape underneath for added measure. So my theory with this car is that if it isn't safety related then let your problems accumulate and allow your car a dignified death. I spent money on repairing my first car foolishly and got burned big time.

Possibly the largest motivator to fix the muffler was my girlfriend who says the noise bothers her. Maybe I'll point her to the dollar store cotton balls ^_^

[Thymeclock]

Originally Posted by Bdorion1

It did pass inspection only a week ago. I was curious if the guy at the shop would say anything about the missing muffler/ ecomods I've done but apparently he was too busy to ask, or had seen so many strange things on peoples cars he just didn't care. The "cat still hanging in there" was probably my saving grace as it allowed me to pass emissions. (That phrase conjures up images of a haggard feline clinging desperately to the underside of my car. Ha)

And you say you are in NY state? You are obviously not in the downstate area or maybe you "bought a sticker".

Last year one of my very much older cars (a 1988) had a small rust hole in the tail pipe (not the muffler). They refused to inspect it saying the emissions test might not read accurately. I promptly cut and clamped on a new tailpipe to get them off my back.

Since then (just this year) the old dyno test was scrapped (because the testing machines were absurdly complex, hard to maintain, constantly breaking down, and besides, nobody has a 20+ year old car anymore except me), so now my car passes inspection without any emissions test at all! Maybe yours did the same. Or, if you live in rural upstate, there isn't any emissions test there, anyway.

As much as I like DIY, I am a 21 year old still in college so the welding/ metalworking/ garage thing is beyond my current ability (unfortunately).

As predicted, apparently your whole exhaust system is like swiss cheese. Basically you only need some replacement pipe and/or muffler bandage, simple hand tools, safety goggles to keep the rust bits out of your eyes and the willingness to crawl under the car and get dirty to repair the exhaust system. Have you ever had a front exhaust pipe break off? Mine did on my very first car when I was 21, but at least I repaired it - because a 5 liter, American engine in a car weighing over two tons without any exhaust at all is deafening - it sounds like a plane taking off...

Now as to why I am such a cheap SOB...
Possibly the largest motivator to fix the muffler was my girlfriend who says the noise bothers her. Maybe I'll point her to the dollar store cotton balls ^_^

Yes, you are exactly that which you described yourself. It's only a matter of time until she wakes up, realizes it and dumps you.

Or you could try patching up your exhaust, before you both end up having monoxide poisoning in addition to unrequited love...

[Bdorion1]

Well I know there is a difference in cars after 1996 because they have an OBD-II port. Its my understanding the emissions test is all electronic? Maybe thats a misunderstanding, but in my mind a muffler wouldn't reduce any pollution anyways (other than noise) so I don't see how they could fail me just for that. Maybe my mechanic gave me a break, or maybe yours was trying to rip you off by charging you to fix the hole. Maybe someone else has a better idea of how this works than me.

If I'm gonna try to do the repair myself how do I attach the pipe to the triangular shaped hole on the catalytic converter? Or does it have to be a pipe made for this specific car? I guess thats kind of an off topic question for this site, but since you've been through this I might as well ask.

Even more off topic, the gf already knows I'm cheap. We've been dating for years and apparently she finds it endearing or something otherwise she'd be long gone. Although in the short run a big spender is flattering, in the long run I think frugality (read: reduced financial troubles) reigns. Besides, I think saving money is at least 50% of the reason anyone is on this site. That being said, I don't think CO poisoning is high on my list of things to do so I think I'll give fixing it up a shot.

[toc]

Get us some photos, suggestions are better when what's needed can be seen.

I had rivets in mind to avoid welding (I don't own a welder, never welded either).
Silicone or other adhesives came to mind too, but they might not be temperature proof (as it's got to last, duct tape just won't do for this).