Questions about Exhaust systems, Catalytic Converters and Headers/Manifolds

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12
votes
4answers
739 views

How can I tell if I have bad cats?

No, not that cat! Catalytic converters - or "cats" - have a nasty habit of failing with age. What are the symptoms associated with a cat that's gone bad? Are there any tests that could ...
24
votes
3answers
138k views

What does a water like drop coming out of the exhaust of the car signify?

Sometimes while driving in the traffic, I come across a car or two which would be dripping water-like drop from it's exhaust steadily in a break of 4-5 seconds. I tried to ask a couple of people at ...
22
votes
9answers
79k 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 ...
4
votes
1answer
3k views

Car Stalls When Coming to a Stop

Make: Chevy Model: Cavalier (4 cyl.) Automatic Year: 1993 Miles: 230K Normally my Cavalier drives just fine without problems. However, if I drive for 45+ minutes then it will sputter and stall out ...
9
votes
3answers
8k views

Catalysator broken? Odd rope coming out of the exhaust pipe

[UPDATE] SOLVED! Hurray! The muffler had corroded inside and it blocked the exhaust system, making bad to motor. I got it fixed and the car energy efficiency improved from 12-15 liters/100km to ...
24
votes
2answers
2k views

Why do two-stroke engine exhaust pipes look so strange?

Two stroke gasoline engine exhaust pipes are shaped strange. They expand into a wide diameter and then shrink down to a very small diameter where the exhaust gasses emerge into the environment. Why ...
15
votes
3answers
14k 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 ...
27
votes
7answers
5k views

What is the point of the exhaust?

I was thinking today, what is the actual point of an exhaust? Why can't we just have a pipe going out the front of a car instead of taking all the gases to the back of the car? I can only see ...
10
votes
1answer
5k 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 ...
7
votes
1answer
95 views

Locating the O2 sensors and the cat along the exhaust

I gather that the upstream O2 sensor is the one right in the center of this picture. I also gather that the catalytic converter (the "cat") is the bulbous part of the exhaust right behind this sensor. ...
7
votes
1answer
341 views

Why no exhaust gas turbine generator in hybrid vehicles?

I found something interesting on Wikipedia today: a hybrid turbocharger. This is a device that charges a battery with an exhaust gas turbine, and at the same time operates an air compressor using the ...
5
votes
1answer
259 views

Car feels like it's filling up with fumes

I bought a used 2000 volvo s80 with around 93k on the odometer. I was driving the other day and I felt sort of sick. At first I thought it was some dirt on the floor that got into the air. But upon ...
5
votes
3answers
1k views

straight pipes and carb rejetting?

I have a 1984 Honda GL 1200 standard wing and I am going to put straight pipes on it, however some forums say I will need to upjet the carbs, and others say I will not. Has anyone on this site ever ...
2
votes
2answers
1k views

Grey smoke when idling 1999 GMC Suburban, coolant system pressure loss

The most recent update is at the bottom. This looks interesting. The Smoke I'm confident the smoke is from burning oil. It's slightly blue, absolutely not white. If the engine is warm and I am ...
2
votes
1answer
995 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
votes
1answer
175 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 I'...
2
votes
1answer
439 views

Rusty exhaust manifolds

Most of the engine on my 2007 V6 Tacoma is in a really good shape but both exhaust manifolds coming out of the engine block are really rusty. Q1: Is that a reason to worry or replace them, provided ...