1994 Toyota 4Runner with bad muffler/tailpipe – what to do?
November 12, 2013 4:28 PM   Subscribe

My 1994 Toyota 4Runner (V6, RWD) has a bad muffler and/or tailpipe. It runs loud, but not undriveably loud. Today I took a good look under there for the first time since buying the truck (pictures within) and I would like some advice on the best and most cost-effective way to proceed. Bonus mystery switch question at end.

A few months ago I purchased a 1994 Toyota 4Runner. It's got the V6 engine and rear-wheel drive. It's been a great truck so far, but among the handful of minor problems that I knew it had when I purchased it is a bad muffler and/or tailpipe. The first image in this Imgur album contains some photographs of the situation.

The truck definitely runs louder than I feel like it should, and that loudness does seem to be engine noise coming out of the muffler area. It's not insanely loud and it doesn't noticeably affect the truck's driving characteristics, but it's louder than I'd like. This leads me to believe that the muffler and/or tailpipe is compromised, but has not failed completely. (Is that a reasonable assessment?)

As you can see in the picture (full-resolution link) there is a fair amount of rust going on there, including some holes in the tailpipe. Not pictured (sorry about that) is the end of the tailpipe, which terminates in a sort of rusty jagged mess underneath the truck just behind the rear bumper. Fortunately there doesn't seem to be any significant rust elsewhere under there, the muffler seems to be the only part that's affected.

I'd like to know what the best, most cost-effective way is to proceed. Here's my list of muffler-related questions:
  1. Funds are tight. Does this muffler need immediate replacement, or can I wait on it indefinitely until I can more easily afford it?
  2. Is it possible to repair the muffler and tailpipe rather than replace, or would that not be a feasible/worthwhile thing to try to do?
  3. The previous owner suggested sourcing a new muffler from a junkyard – does that sound like a reasonable plan, and if so how much of a pain in the ass would it be to do so?
  4. If a brand new muffler is in order, what is a good model that will give me a nice, quiet, OEM-style sound (not looking for a "performance" muffler here, just a basic quiet one that will last) and which will not be too expensive?
  5. What do you suspect led to the situation pictured, and how can I prevent it from recurring? For reference, the truck is in Louisiana and has been in Louisiana its whole life. It was not flooded in Katrina.
  6. Is replacing a muffler/tailpipe something I can do myself (I am pretty handy and have tools, and am willing to buy some additional tools if need be, but I cannot weld) or would I be better off just getting the part and taking it to a muffler shop or mechanic and having them do it? If so, roughly how much should I expect to pay?
  7. If you think that replacing it myself is within the realm of possibility, can you give me a brief outline of what is entailed? I have the Haynes manual for the truck, but their directions and diagrams aren't always 100% clear. If you know of a step-by-step tutorial for muffler replacement (especially on a 2nd-gen V6 4Runner) that would be especially appreciated.
  8. Is this problem indicative of any more deep-seated issues that I should be aware of?
All answers and advice will be greatly appreciated. I would just take the truck to a mechanic and have them take the problem out of my hands, but funds are tight as I mentioned above so I need to know how high a priority this fix should be and I'm looking for the most cost-effective appropriate solution to the problem. I want this done right, but I need to save as much money as I can without cutting any important corners. Thanks in advance.

Bonus mystery switch question: there is a small toggle switch in the driver's side footwell of the truck which appears (though I am not totally certain) to be wired to the "STOP" fuse in the interior fuse box. Toggling it turns a red indicator light on the accessory panel to the left of the steering wheel on and off, but does not appear to have any other noticeable effect. (I leave it in the "on" position since that is how it was when I bought the truck. Also, the light remains on even if the truck is turned completely off and the key is removed from the ignition.) Here is a full-res view of the "situation". (Note: what appears to be a black wire behind the prominent red wire in the upper-right picture is actually just a shadow.)

When buying the truck, I forgot to ask the previous owner what the function of this switch is supposed to be for. I confess I have absolutely no idea what it does or is supposed to do, or whether it's a good idea to leave it in place, or if I do leave it in place whether I should have it on or off. It's obviously an after-market addition, presumably owner-installed rather than installed by a professional.

The only clue I can think of is that the previous owner's uncle (who owned the truck before the guy I bought it from did) was a paraplegic and operated the truck via hand controls, which have since been removed. I have no idea if that's relevant, but I thought I would include it in case it gives someone a lead. I would love to know what this switch does and whether there is anything I need to do about it.

Thanks again in advance for your answers. I appreciate your thoughts and advice.
posted by Scientist to Travel & Transportation (15 answers total) 1 user marked this as a favorite
 
Response by poster: (Note that "I am pretty handy" should be read as "I am pretty handy and also willing to bust ass over a weekend on this, learn as I go, and possibly screw it up.")
posted by Scientist at 4:42 PM on November 12, 2013


Exhausts are not "hard" to deal with. It's a pipe with hot air. They rust out really easily because the high temps and moisture involved in combustion. That actually makes them harder to deal with because the rust gets on everything.

You could totally do it yourself. But me, personally, I'd take to a muffler shop and have them replace from the catalytic converter back. Probably cost 200 bucks. Too much pain in the ass for me, my friend.

The only way to know definitively what the switch does is to follow the wires. On first blush, I wonder if it disables the brake lights. The fact that it is tied into the stop circuit doesn't necessarily mean anything - it could just be that circuit is energized when the car is on or that it was handy.
posted by Pogo_Fuzzybutt at 4:50 PM on November 12, 2013


The switch might be a brake light kill switch. People who make a hobby out of speeding use them so cops can't tell when they're slowing down after getting tagged with radar or laser. So do the brake lights keep working with the switch on?
posted by zsazsa at 4:51 PM on November 12, 2013 [1 favorite]


Unless you're handy at welding relatively thin (and possibly dirty/rusty) pipe overhead, this is not a DIY job. Bolt-ons are a PITA on rusty old pipes and never work as well as you think they should, and buying a pre-bent rear pipe is going to be expensive. Junkyard exhaust systems on old cars are rarely worth the money since they're in unknown condition and generic mufflers are so crazy inexpensive. For reference, our 94 Toyota pickup (same engine, etc.) generic muffler install runs $100 total: $60 muffler, $40 labor. Replacing the rear pipe at the same time is ~$50, if I recall. This is in southwestern Virginia.

You can hold off replacing the muffler and rear pipe for essentially forever. (Does your state/county have safety or emissions inspections?) The only real concern is that a leak anywhere in the exhaust system can cause fume ingress into the cab. So replace it when you can and, until then, crank the window down a turn when you stop for any length.
posted by introp at 5:00 PM on November 12, 2013 [1 favorite]


Your catalytic looks fine. I see holes in the exhaust after the muffler, but that muffler actually looks pretty solid too. Also, it looks like the tailpipe leading out of the muffler is just shoved into the muffler hole. Is that how it is? That would make it louder for sure. You could take it in to an exhaust shop and have them give you an estimate. I would not tackle exhaust work yourself unless you have a full complement of tools and don't mind getting totally filthy. Are you in a state that has emissions testing? That may affect what you want to do too.

As for what that switch is, your suspicion about hand controls make sense. The "stop" fuse is the circuit that actually lights up when the brake pedal is pressed. Since the pedal would never be pressed, the hand-controls setup must have some way of turning the brake lights on and off.
posted by cosmicbandito at 5:15 PM on November 12, 2013 [1 favorite]


after a quick search, I'm wrong the hand controls. They don't require a brake light switch because they actually move the pedals. So I'm changing my guess to "fake security system light". Turn on the switch, and you've got a nice lit up LED on the dash the looks like an alarm. The "stop" circuit is used because it has power even when the ignition is off.
posted by cosmicbandito at 5:21 PM on November 12, 2013


Best answer: Surprised no one has already said this: Muffler tape, dude. As a proud driver of piece of shit cars for many years, muffler tape is your friend. Watch a random youtube on how to properly wrap it and then enjoy quiet(er) driving for, well, however long until your swamp-ass roads rust the son-of-a-bitch out again.
posted by klangklangston at 5:30 PM on November 12, 2013 [3 favorites]


I picked up a used OEM stainless exhaust for my Pathfinder (87) at a wrecker for $75. I brought my tools and harvested it myself, then popped it in. It lasted about 100k km, and was still in perfect shape when I got rid of the car. This was ten years ago, but it's a solution if you can find a good used part.

Keep in mind that I'm in a location where emissions don't need to be checked and the exhaust was from a later model that had an incompatible catalytic converter. You might have to be a bit more exacting.
posted by klanawa at 6:33 PM on November 12, 2013


1. It doesn't need to be replaced immediately, but it may become (annoyingly) loud, affect gas mileage, and will probably fail you during an emissions test (if applicable in your town/state).

2. Not worthwhile considering how much a replacement would cost.

3. While I'm all for some junkyard digging (went out to one today in fact), the muffler is welded to the catalytic converter, which means you would have to cut it off at the yard, remove it from the hangers, etc. Kind of a pain in the butt in my opinion, and there's no guarantee you can find a replacement in better condition. See 2.

4. Hop online to Advance Auto Parts, AutoZone, O'Reilly, etc and see what OE-equivalents are available. You should be able to find one pretty easily, probably for <>
5. It just happens and is really not all that surprising for a 1994. The only real option to slow this from happening again would be to buy a stainless steel muffler and tail pipe, but considering the original lasted 20 years, this probably isn't worth it.

6. I think this is definitely something you can do yourself. It's a pretty simple replacement, and there's absolutely NOTHING you can do to mess it up. You'll have to hack-saw off the old muffler from the catalytic converter, then join the new parts with a coupler (available at auto parts stores). The height of the 4Runner makes it super easy.

7. See 3.

8. See 5.

Good luck, and post some pics of those dirty hands!

P.S. The switch definitely is not factory... seems to me it just adds the character of the 4Runner! haha
posted by mrrisotto at 7:10 PM on November 12, 2013


Scientist: "Funds are tight. Does this muffler need immediate replacement, or can I wait on it indefinitely until I can more easily afford it?"

Your muffler looks fine, it's just your pipes that are holy. If money is really tight a couple of muffler clamps (like $1 each) and any sort of steel (a tin can the approximate size of the tail pipe works pretty good) that you could wrap around the pipe will make a significant difference on how noisy it is. Don't worry about anything aft of the muffler as far as noise goes.

If not cutting off a tailpipe section at a junk yard and than clamping it on with band clamps is something anyone with a hacksaw and wrench can do and around here that'll cost about ~$50.
posted by Mitheral at 7:19 PM on November 12, 2013


5. Tailpipes eventually rust out even in climates without major sources of corrosion. I drove a Datsun that was 17 when I bought it, and had never been driven anywhere but Portland OR (where they sand the roads but don't salt), and the tailpipe developed holes like yours and eventually the end fell off.

It was cheap to replace and the reduction in sound (and in fear of asphyxiation) was remarkable.

I like cosmicbandito's explanation of the switch. It's also possible there was a secondary emergency braking system attached to that switch (presumably no longer attached but with the switch and light still intact.)
posted by gingerest at 8:53 PM on November 12, 2013


I'm in the UK so my answers may be irrelevant. Specifically about low cost options...

I drive a 99 Corolla SR that was limited enough in numbers that they imported them from Japan rather than make them in the UK with the rest or the European Corollas. As a result, a replacement exhaust is about 400 quid ( 500-600 dollars ).

So, instead of taking it to the local car exhaust place, I took it to a place that does cars and lorries ( the kind of place that does roadside tyre replacements for lorries ) and they built me a custom pipe for under 100.
posted by sodium lights the horizon at 1:35 AM on November 13, 2013


Best answer: Funds are tight. Does this muffler need immediate replacement, or can I wait on it indefinitely until I can more easily afford it?

You can bodge this up and wait, no problem.

Is it possible to repair the muffler and tailpipe rather than replace, or would that not be a feasible/worthwhile thing to try to do?

The silencer (muffler) looks to be fine. The pipe itself needs patching up.

The previous owner suggested sourcing a new muffler from a junkyard – does that sound like a reasonable plan, and if so how much of a pain in the ass would it be to do so?

Forget this idea. Much more hassle and expense than just fixing it with a beer can (Tall one) - Get some hose clips, some exhaust repair paste and some of the exhaust tape mentioned above. Tape over the hole and about 2 inches either side of it. Smear with exhaust paste. Cut the top and bottom of the beer can off and split it lengthwise. Wrap the beer can over the tape and make sure it overlaps. Hose clamp the beer can down as close as you can to just outside where the hole is. repeat for the other holes as best you can.

Exhaust tape will fix the hole fine and will cure off well for the bendy bits, but supporting it with a beer (or coke!) can will provide a more long term solution. Then just price up a new exhaust from the catalysts back, and save up for it. Leave the money somewhere until the beer can fix fails and then get it swapped out for a new one.

If a brand new muffler is in order, what is a good model that will give me a nice, quiet, OEM-style sound (not looking for a "performance" muffler here, just a basic quiet one that will last) and which will not be too expensive?

Just get an aftermarket one of good provenance. OEM equivalents are fine from a reputable exhaust place.

What do you suspect led to the situation pictured, and how can I prevent it from recurring? For reference, the truck is in Louisiana and has been in Louisiana its whole life. It was not flooded in Katrina.

It's perfectly normal exhaust wear. They are a part with limited life. Nothing unusual happened. It's about as expected as brake pads wearing out.

Is replacing a muffler/tailpipe something I can do myself (I am pretty handy and have tools, and am willing to buy some additional tools if need be, but I cannot weld) or would I be better off just getting the part and taking it to a muffler shop or mechanic and having them do it? If so, roughly how much should I expect to pay?

Just get it changed at an exhaust place when you can afford it. IT's genuinely not worth the hassle to do anything other than a beer can bodge to an exhaust unless it bolts on (which yours doesn't). Exhausts are shitty to get off and annoying to replace. Shop around but be aware the cheapest exhaust will likely last the least amount of time.

If you think that replacing it myself is within the realm of possibility, can you give me a brief outline of what is entailed? I have the Haynes manual for the truck, but their directions and diagrams aren't always 100% clear. If you know of a step-by-step tutorial for muffler replacement (especially on a 2nd-gen V6 4Runner) that would be especially appreciated.

Don't bother, seriously. It's a really easy job if you have a ramp/lift, cutting tools, oxy-acetylene torches and/or air hacksaws. Dicking around on the floor on axle stands and doing it yourself without the brute force tools is a lot of hassle, mess and time. It's just not worth it.


Is this problem indicative of any more deep-seated issues that I should be aware of?

Again this is not a problem. This is normal. Is this your first car? Do you not know that exhausts just rust away eventually? Exhaust gases are remarkably corrosive things and only stainless steel (really expensive) exhausts will last appreciably longer.

Not pictured (sorry about that) is the end of the tailpipe, which terminates in a sort of rusty jagged mess underneath the truck just behind the rear bumper.

This is more of a concern potentially and would make me replace the exhaust as soon as I had saved the money after the beer can bodge. Exhaust gases getting into the car is a bad thing. If the exhaust doesn't exit far enough away from the vehicle it can be drawn into the car at lower speeds. If you start to smell exhaust more than momentarily or get head aches when driving, change the exhaust immediately. If it is well below the body of the car and fairly close to the rear of the chassis you may be ok, but keep an eye on this. Keep the heater/aircon fan in the car at a higher speed than you normally would (to try and positively pressure the interior) and you'd probably be ok. (as in 2 or 3 rather than 1 or off). That's possibly overkill, but8 it's worth doing to be safe, I think.
posted by Brockles at 6:26 AM on November 13, 2013


Best answer: It's obviously an after-market addition, presumably owner-installed rather than installed by a professional.

Good god, that looks like a wiring job by a blind car thief, rather than an 'aftermarket' solution. You'd need to trace the other wire that come from the switch to see what that does. The red wire you are showing is likely to be the feed wire, rather than the output. Try and pull the switch out or remove that panel/stick your head behind it and see where that other side goes to.

What a bodge job. I'd make removing that a priority, frankly.
posted by Brockles at 6:30 AM on November 13, 2013


Response by poster: Not my first car, but my first one that was old enough to have worn out a muffler. I tend to learn car-related stuff on an as-needed basis, and this is the first time that I've dealt with this issue. Good to know that I can bodge it back together for now, and that getting it properly fixed won't be too expensive when it comes time to do that.

And I'll figure out where that switch goes and get rid of it. It doesn't seem to be hurting anything, but I agree that there's no good reason to leave it there if it's not doing anything worthwhile, especially given the rather ham-handed way in which it appears to be wired up.
posted by Scientist at 10:58 AM on November 13, 2013


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