Ok guys, I just took it to the dealership and they confirmed it is a damaged flexpipe. Is the car safe to drive? I smell fumes.

 

NO! Unless death appeals to you.


This is the first entirely new description of a failed flex pipe in a long time. I still have no idea how it is related to acceleration or gas guzzling.

 

Certainly not, but it's true. Don't ask me why this is causing my problems, but it is. It is sucking the gas like crazy, I used to get 30 mpg, not now! I may get 25! And you hear the "shh" sound and the tail pipe is extremely LOUD!

 

Besides leaking exhaust into the cabin, the leak in the flex pipe is throwing off the engine's normal operation, so a mileage drop is not too surprising.

It's something to get fixed A.S.A.P.

But before committing to using the dealer, check with your local exhaust/muffler shops to get quotes from them. Dealers are the most expensive option when in comes to rectifying this problem.

 

If it was me, I'd just drive with the windows open - to ensure the fumes don't build up - and run it into a local exhaust shop like 843de says.

The repair should be in the neighbourhood of what guys? $150 ??????

 

I think she may be covered by the EPA warranty. Check it out, it is different for different years.

 

I asked the dealership and they said I was past it. It was 8 years/80,000 miles. Mine has 99,000.

 

This is from the chevy website:

Emission Control Systems
Defects and performance for car and light-duty truck emission control systems are covered for the first 2 years or 24,000 miles, whichever comes first. From the first 2 years or 24,000 miles to 3 years or 36,000 miles defects in material or workmanship continue to be covered under the New Vehicle Limited Bumper-to-Bumper Warranty coverage. Specified major components are covered for the first 8 years or 80,000 miles, whichever comes first. Defects and performance for heavy duty truck emission control systems including those found in 6.6L Duramax® Diesel Engines are covered for the first 5 years or 50,000 miles, whichever comes first.
- Refer to your Warranty and Owner Assistance Information booklet for California emission control system warranty details.

 

As to how this can effect mileage, the biggest way it effects mileage is the O2 sensor giving an artificial lean reading because of the leak. So extra fuel gets added to the mix.

 

If the leak is bad enough to affect the HO2 sensors to the extent of affecting fuel consumption there WOULD be a CEL, I know I've had it twice. She never mentioned a CEL, so I never really went there. And I still don't get "accelerating problem" at all, since the only mentions of a noise was the gas flowing and tail pipe.

The common symptom is "a loud whooshing sound upon acceleration", many times with a CEL (p0449, if I remember right). Most times the counter jockey thinks that Bank X lean or rich means something is wrong with either the injectors or the HO2 sensors.

843de must know "wimmen talk" better than me to get the translation that good.