Questions about Exhaust systems, Catalytic Converters and Headers/Manifolds

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1
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1answer
475 views

What could be causing a distinct exhaust drone in a tight band around 3250 rpms on a 2004 Subaru WRX?

EDIT: Additional information provided by LovelyWife(TM) - listening outside the car, she has proclaimed that the rattle / buzz / drone / resonance is coming from the front of the car and sounds like ...
2
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3answers
6k views

Rattle on Ford Focus, suspect heat shield

Ford Focus 1.8 Ghia '99 V A little while ago a large section of the aluminium heat shield above my exhaust came loose. Being in a situation where I needed to keep going and without tools, I crawled ...
3
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1answer
1k views

Is it possible to use biodiesel in a BMW 335d if I remove the DPF and remap the ECU?

The new (2009-current) BMW 335d sells in the U.S. with a DPF to reduce emissions, but which prevents the use of biodiesel. I've read about people removing the DPF and re-mapping their ECU to get ...
2
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1answer
138 views

How should I diagnose an exhaust “howl” when descending through 3200 rpms?

As mentioned previously, I have a 2004 WRX wagon with a stainless Prodrive circular-tip axle back installed around 2006. Lately, the weather has been nice enough to drive with the windows open and ...
1
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2answers
420 views

Why would gasoline engine exhaust smell like perfume?

Quite often I encounter a vehicle that has exhaust with rather sharp smell similar to perfume. As far as I know this is attributed to the engine malfunctioning - normally working engine will exhaust ...
11
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3answers
3k views

When car is standing still, I smell Diesel exhaust. Why?

In my 2003 Opel Vectra, the cabin air smells of Diesel exhaust while stopped at e.g. a red light. The exhaust smell goes away when driving, and it also doesn't come back if I turn the ventilation off ...
3
votes
3answers
234 views

How much of the exhaust is the “cat-back”

My brother-in-law's car has just failed inspection. One of the items listed was a "cat-back." Since the bill is astronomical, I was wondering how much of the exhaust system is encompassed in this term ...
12
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4answers
22k views

What is the best way to remove a stuck/rusted exhaust bolt?

I'm trying to disassemble the exhaust system on a 2000-2003 nissan maxima and I'm having trouble removing one last bolt.. its got a 14mm head and its just plain STUCK. I've tried soaking it overnight ...
2
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1answer
432 views

Are there any alternatives to the OEM muffler for a Volvo XC90?

I've been looking for an alternative to the OEM muffler for a Volvo XC90 2.5T AWD. There are a number of other Volvo vehicles that use the same drivetrain, but not one of the national muffler shops ...
7
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1answer
2k views

What are the tell tale signs of a catalytic converter that might be going bad?

I've owned two vehicles whose catalytic converters were recalled due two a couple of reasons: one being the quality of the CC and the other being a reduction in power due to a material building up and ...