Exhaust / Oxygen Sensor Question

[TimRXUV777]

Hi,

Well I just got back from a really "informative" session with the local Midas manager.

Background: This previous weekend we took my Envoy to various graduation receptions. On the way to one, it felt like I blew a hole in my exhaust. Checked when we got there and there was a hole in the exhaust, right where one of my O2 sensors used to be. I had blown it out of the mounting hole. On Monday I scheduled a Midas visit.

Today: I took it to Midas today mid-morning. The wonderful people at Midas told me someone previous to me had stripped the oxygen sensor mounting threads and had welded the O2 Sensor in. I have driven my Envoy thousands of miles and not had a problem with it. The Midas manager started quoting me half a dozen parts to solve this issue including a new cat. WTF?? I told him that since I have driven my truck thousands of miles with the sensor welded in.. to just weld the sensor back in. The manager told me that welding it in would not be up to Midas's Standards of Service. I felt like telling him where he could stick his standards. But instead just got into a yelling match about the fact that fixing it in the most expensive way possible was not a "Standard". I told him Midas had a really nice scam going on. He told me to take my truck and go - which i did. I did not wait and he was unwilling to write me up a work order detailing how much it would cost to add all those parts.

What would you do in this situation? I am a student, work a measly part time job that was probably not even going to get me through the summer. Now I have a truck that sounds good but is really loud? I am a mechanical design engineer, and can see that one way to solve this would possibly be to weld a 3/8" or so thick threaded steel washer in over the bossed hole in my exhaust and just thread a new sensor into that washer? I don't have $300+ to add a bunch of unneeded parts just to fix this issue.

 

[Sparky]

Which sensor blew out?

If it is a post-cat sensor it isn't that big a deal to weld a new bung in the pipe.

 

[The_Roadie]

....I took it to Midas today mid-morning.

There's your problem. Chain stores are only as good as the local manager, and too many are all about the commissions, since they don't have the same sense of cultivating a local loyal client base because people aren't as loyal as they used to be. And much of their clientele is transients who will never be back, so they only have one chance to make all the profit possible.

Locate a one or two-man independent shop with no franchise overhead fees and just tell him what you want. Use Yelp to check their reputations. You need a small muffler shop guy with a good attitude to helping students and a welder.

 

[Texan]

As Sparky asked, which sensor? You or a friend should be able to visually verify if it was welded in.
Is the sensor hanging loose, still connected to the wiring harness?

 

[TimRXUV777]

Show me some pictures of all 4 sensor locations and I will tell you which one it was. Yes it was hanging loose. It had a bunch of crud on it difficult to tell if it was welded.

 

[Texan]

On a V8 there are two sensors on each side of the vehicle. Driver side (bank one) and passenger side (bank two). One sensor ahead of the
catalytic converter and one sensor after the catalytic converter. Did the check engine light come on and set a code? If so, what is the code.

 

[TimRXUV777]

No CEL. Driver's side.

 

[Sparky]

Visible from the engine bay just off the manifold on the engine, before the cat, or is it hanging down underneath the truck past the cat?

I suspect that it is the one past the cat if it is running fine with no CEL.

 

[TimRXUV777]

Yep Driver's side and I believe it was past the cat.. Do the cats run longitudinally or transversely? It would be really helpful to see a photo of an Envoy from underneath and the major components labeled? I didn't spend much time under there besides noticing the location of the sensor and how primarily rust free the underside was. Didn't really try to figure out where the cats were in relation to it. Not to mention I was seeing red in a bunch of different ways after he mentioned that I would need a new cat because some threads on a sensor were stripped. I like how most things seem to be designed to line people's pockets inappropriately. A new cat and assorted pipes needed because some unknown lameass stripped some threads on a minor part pretty much only needed to keep the tree huggers happy??? Nice.. where is the little red f'in' icon with horns when you really need him?

 

[Sparky]

Sounds like a simple easy fix then more than likely. new bung welded in, maybe a patch on the pipe section right there, new sensor perhaps (NOT Bosch, GMs don't like those usually), and done.

 

[TimRXUV777]

Yep, I would think relatively easy. Just really surprised that Midas was not more accommodating towards that solution. Now, like roadie said, I just have to find an independent exhaust place or someone talented enough to do the fix.

 

[TimRXUV777]

It was the sensor numbered 17 on the right in this diagram, driver's side of Envoy. I also think my truck has a transverse mounted cat on the crossover pipe shown here without one?

 

[The_Roadie]

You need to buy yourself some talented friends.

 

[TimRXUV777]

LOL. Does anyone know what size the threads on these things are? Does anyone make a steel washer with these threads that would work to weld in?

 

[triz]

There's your problem. Chain stores are only as good as the local manager, and too many are all about the commissions, since they don't have the same sense of cultivating a local loyal client base because people aren't as loyal as they used to be. And much of their clientele is transients who will never be back, so they only have one chance to make all the profit possible.

Locate a one or two-man independent shop with no franchise overhead fees and just tell him what you want. Use Yelp to check their reputations. You need a small muffler shop guy with a good attitude to helping students and a welder.

Kind of like the time my ex took her Rav4 to Toyota because she damaged her exhaust a bit. They quoted her 800 dollars for a new one. She called me and I told her to get her keys and get out. I took it to a reputable exhaust shop and $10 dollars later her exhaust was fixed with a new hanger. Needless to say I wrote a nasty note to the Toyota corporate and the owner of the dealership with copies of the receipt.

At the OP a standard bung should get you through. Find an independent shop, list your location. Someone might be able to point you to a decent shop.

 

[TimRXUV777]

..... I took it to a reputable exhaust shop and $10 dollars later her exhaust was fixed with a new hanger. Needless to say I wrote a nasty note to the Toyota corporate and the owner of the dealership with copies of the receipt.
At the OP a standard bung should get you through. Find an independent shop, list your location. Someone might be able to point you to a decent shop.

I am currently in Fargo, ND. How do you find a reputable shop? I called and left a complaint with the Midas Customer Satisfaction department. I don't expect any real results from that, mainly just had to blow off steam. Please explain what a bung is.. all I can think of when i hear that term is "Beavis and Butthead".

 

[Sparky]

an exhaust bung is just a threaded hole for the O2 sensor that is designed to be welded into exhaust pipe.

Yelp may be a good source.

 

[TimRXUV777]

Which is what i thought of even though i didnt realize it's called a bung. Alright, will try Yelp.

 

[TimRXUV777]

I have been driving my Envoy with the loud exhaust and the 02 Sensor hanging clear of its mounting. I am planing on taking it to an independent muffler place on Monday and getting a bung welded in. The engine threw a code tonight the CEL came on solid - no blinking. This O2 sensor issue is probably the cause of this code correct?

 

[Mark20]

Really need to read the code. Code be related or something else that timed it just right.

 

[Sparky]

Wouldn't surprise me as the sensor is reading everything blowing by instead of the exhaust stream, but I'd get the code read (for free at Autozone) just to be sure.

 

[TimRXUV777]

Thanks for your help. I got a bung welded in at a local muffler shop for about $33 plus the cost of a new O2 Sensor. The shop ordered the sensor from O'Reilly's for like $80. I asked what brand it was since it sounds like our trucks have issues with anything but Delco. It's a Bosch, am I going to have issues? The CEL code was for the O2 Sensor they cleared it and everything is working fine right now.

 

[Sparky]

Post cat O2 being a Bosch may not be as likely a problem. I say just run it for a bit and see how it goes. All it does is check the cat and not affect the operation of the engine.

My truck actually ran with a pre-cat Bosch O2 for a couple years without issue.