New muffler/resonator pipe for '99 3.5L

1999/3.5L-GX/94K

Hi gang.

I just had the olds into the shop for a few things; new tranny fluid, oil change, brake inspect, rotate/balance and some other minor stuff.

I've been having a whirring kinda sound that I thought was coming from under the hood when accelerating at around 2-3k rpms. Turns out my exhaust is rotting out. I've been quoted $500 for the job and am wondering if I should shop around a bit. The parts (napa) come to about $240.

Five hundred clams is a bit much for me after just spending $300 on the other stuff. This car has spent it's 94K in S.New England climate, if that matters to anyone.

Thanks for your time.

EXH 55234 EXTENSION PIPE
$95.49 $95.49
EXH 55235 MUFFLER
$144.00 $144.00
BK 7335336 Exhaust Clamp - Universal
$1.49 $1.49

Hi
I don't know what your installation options are, but rockauto.com has Walker brand exhaust parts for about $100 less, prior to shipping of course.

Good Luck

OE exhaust parts are very expensive compared to aftermarket. The "problem" with most of the aftermarket stuff is that its going to make your car louder. Which may or may not be a problem for you.

Depending on what all is rotting out, there are many options. What all needs replacing? Have you crawled under there yourself to check things out?

You can get mufflers for as cheap as 20-30 dollars or as expensive as you can imagine, they just have different sounds and different quality.

As for the catalytic converter, Magnaflow High-Flow cats can be had for about 50-60 bucks, but I think they are too wide to fit into our location. Im using basically a no-name brand that I got off of Ebay for about 45 bucks, I coupled that with a u-bend delete and it seemed to pep the car up a bit.

Walker products mentioned above is basically the same company as Dynomax, should be a good product.

I say take advantage of this problem to get yourself a better sounding/performing/looking car..but I say that to every problem.

I have a 98 3.8 engine and had my resonator removed due to rot. Midas put in a glass pack muffler pretty cheap. I'm thinking in the under $200 range. Sounds fine and it has been 10,000 miles.

200 bucks for a glasspack install is pretty gosh darn high as far as im concerned.

You can pick up glasspacks for 40-50 bucks shipped, and the install price should be about the same.

But yes a glasspack is probably a good solution to a bad resonator, as actual resonators are quite a bit more expensive.

200 bucks for a glasspack install is pretty gosh darn high as far as im concerned.

You can pick up glasspacks for 40-50 bucks shipped, and the install price should be about the same.

But yes a glasspack is probably a good solution to a bad resonator, as actual resonators are quite a bit more expensive.

45 bucks for a glasspack? thats a lil high still. check out Advance Auto, they have glasspacks for like 26 bucks! i was gonna get one to spice up my exhaust a bit but instead settled for a louder muffler.

99/3.5GX/94K

Hey folks.

So I got around to getting some more estimates today and ended up getting the job done for $145.

Like I says, the first mech. quoted me $500 for the job. The first place I stopped at today (a newer Midas shop) said $550, told me I needed everthing to the rear of the cat. converter replaced. Then I stopped into a Meineke just down the street.

This guy (pretty sure he was the owner) seemed to think it was a pretty silly idea to replace the whole schmeal and quoted me $150 to do a cut and weld job on just the resonator section. Needless to say, I was surprised at how much less it was. I didn't plan on having the job done today, but the price was right and he said it should take about an hour, so I was down with that.

They welded in a new resonator and about 6-8 inches of pipe on either side of it. I can't tell you what type of resonator was put in, but it's very quiet and has a one-year warranty. The part# listed on my bill is "19670U (MAR)" price $66. I did a few searches but couldn't find the part listed online anywhere.

I guess there's a possibility this'll end up being a "get what you pay for" situation, but I don't think so. The place was run by a 50ish fello who seemed to really know his stuff. Said he had a relative with an Intrigue, and I got the feeling this was the fix he'd do on his own car.

I gotta say, I didn't have a great deal of confidence when I first walked in to the place. Compared to the spotless new shops I'd been to first, this place was a bit of a hole, the sorta shop typical of the 1970s (including music and a broken TV from that era, incidentally).

The place has been around since the early '80s (used to be located across the street), and I really hope it'll be around for a lot longer. I don't gotta tell ya how nice it was to spend $350-400 less than I was expecting to. It was also nice that the cost was actually a bit lower than the estimate, IME it's usually the other way around. $66.49 for the pipe, $70 for an hour of labor and $8.19 tax for a total just under $145.

I guess I've had a holey resonator for a while, but I don't know if my car's ever been this quiet since I bought it 2.5 years back. It may be purely a psychological effect, but the response of the olds after getting the work done seems SO much better now that it's not so noisy. Like the noise made the engine seem as if it was struggling.

Now if I could just finally figure out why I've been getting such crap mileage for the past year or so. 105 miles on a half tank (on the gauge) of city driving is my latest reading.

Like I've said, I know squat about cars. But is it possible the holey exhaust was causing my MPG issues? Like maybe it reduced engine pressure or something? Or I'm just thinking wishfully?

Happy Holidays!

You should probably start a new thread for your gas mileage woes, but for now I would say a good tuneup would be a good place to start. Plugs, PCV valve, and definetely an oxygen sensor at your mileage, especially since youre getting that bad of mpg. Id say the O2 sensor is really the cause of your troubles, even if it isnt throwing a code.

Thanks, littlehoov.

I think I may've started, or added to a thread about the bad mpg a while back. It's been really poor for over a year now (I don't drive the olds much, just 10k in the past 2.5 years).

When the problem first started I did have new gm platinums put in, plus some $180 fuel system cleaning, fuel/air filters checked out okay, ran some chevron techron thru it and just put in a new pcv valve a few months back. People have suggested it may be the O2 sensor, but when I'd mentioned that to my last mechanic he kinda blew it off saying I'd get a check engine indicator if it wasn't okay.

I think I will get it replaced soonly though, probably at the shop that just did my resonator. Am I remembering correctly that there are 2 O2 sensors, one in the engine, and one in the exhaust or something? Is it just the engine sensor I should have replaced?

Sorry for all the questions, but if anyone could give me a ballpark estimate of what it should cost, I'd apreciate it. Should I buy the sensor online from gmpartsdirect or another discount site?

I know, I know, maybe I should've started another thread. But it started out as a reply to littlehoov and then I just got carried away with the Qs. Glargh!

Thanks y'all.

Your o2 sensor can become extremely sluggish and cause poor mpg LONG before it throws a code, they usually dont throw codes until they are just straight up dead.

Yes there are 2 of them, one in the exhaust manifold and one behind the catalytic converter. The one in the exhaust manifold has a large effect on the fueling of the car. The one behind the cat mainly functions to see whether or not the cat is working properly, it does under some cases control fueling, but not very often and not enough to worry about as far as im concerned...leave that one alone.

As for what it would cost, it might be a bit expensive to pay someone else to do it. You can get the part from some places online for 60-70 bucks I think? But buying new from retail is more in the neighborhood of 90-100, and if you go dealership its even more than that. Its also somewhat of a pain to get too, but should be no more than an hour labor.

Personally I would buy it online and change it myself, its not a hard job, you would just need some patience, and would more than likely need to borrow a special socket from some place like Autzone, but other than that its a pretty simple and straightforward repair.

I assume youve sat down and actually done the math to figure your gas mileage and arent just going off the gauge right? Because my gauge is horribly inaccurate, its a common problem, so if youre basing it off the gauge you might want to crunch the numbers.

With all the stuff youve had done to the car, it seems like the only thing left to cause bad mpg is a bad oxygen sensor or a heavy foot. I dont think your exhaust was causing any performance problems, I dont see how it could that far back in the system, but I guess it is possible.

Thanks for the info, hoov. I'm sure about the bad mileage. I reset the trip odo at every fill up and divide the miles driven by gallons put into the car. I've been getting anywhere from 14-17mpg for the past year (almost all city), whereas it was a solid 19mpg for the first year I had it. I also tend to drive pretty conservatively.

I'm not sure I'd be able to do the job myself as I've no ramps or tools, plus it may be hard to arrange for someone to lend a hand and I just don't know cars very well.

Yeah that's some pretty poor mileage. The absolute worst mileage Ive ever gotten is 19mpg and that was driving the crap out of the car the whole tank:)

If you don't feel comfortable doing it, don't do it I guess. I just hate to see people pay more money to have someone else do something. Just in my nature I guess.

Someone who knows what theyre doing should be able to hook your car up to a scanner that will let them read the data from the O2 sensor as well as all the other sensors, they should be able to tell whether or not its acting sluggish by that. But the chances of finding someone to do that for you and be completely honest with you are slim. Mechanics are kind of like doctors, if you walk in telling them whats wrong already it really messes with their head.

Before you try changing the O2 sensor, are there any driveability issues that youre having? I know you said youve already had a good tune up, what about the tires? Do they have good pressure in them? Should be about 33psi or so. Any tire balance or alignment issues? Does the car drive straight easily on its own? Does it start vibrating at higher speeds like around 60-65 then smooth back out around 80? That one might be hard to test living in the city:)

Thanks again. I had the tires balanced about a month back. All of them leak some, 3 lose a psi or two per week and one, which was supposedly repaired leaks a psi/day or so. I'm at the air pump every two weeks or so. Actaully I went out to the car this morning and the leaky one is flat. Some repair job, shish.