Linked Questions

4
votes
2answers
1k views

Bad Cat? Bad smell in Car when heating on [duplicate]

Have a 2004 Toyota Corolla with about 110,000 miles. When I ride the car with the heat on, every now and then it smells like rotten eggs. I looked online and people say I may have a bad catalytic ...
18
votes
7answers
10k views

Why or why not increase engine efficiency by running the car “fuel-lean” (using a turbo or supercharger)?

Everyone wants their cars to use less fuel, right? I read the following passage about running the car fuel lean from this website: Run the engine fuel-lean, that is, use excess air. It is well ...
11
votes
3answers
103k views

Check Engine code P0420 Catalyst efficiency below threshold bank 1

After months of normal driving with no problems, my 2003 Honda Civic EX check engine light came on during a long trip. Got it scanned and it's P0420: Catalyst efficiency below threshold bank 1. They ...
9
votes
2answers
2k views

What is the “propane test” and how is it carried out?

This test is often mentioned in the context of figuring out what's wrong with a car engine's operation (misfires, hesitation, poor fuel economy, etc.) What is this test and what does one need to ...
7
votes
3answers
2k views

2003 Toyota Corolla, 185k: erratic OBD codes, fuel smell, other symptoms

TL;DR: O2 sensor data, thermal measurements, and physical resonance tests all point to a failed Catalytic converter. Here's the back story. MIL illuminated with codes P0440, P0420, P0404. Around this ...
13
votes
2answers
8k views

Rough idle @ stoplights - O2 sensors reading zero voltage

I have an '05 4.7L Dodge Dakota that has had an issue with rough idle for over a year now. It seems to only happen after coming to a stop at a traffic light. It seems to happen more often after having ...
9
votes
2answers
4k views

Troubleshooting Low Turbo Boost

I'm starting to suspect that the smoke and low power (I'm pretty sure it is not "limp mode" just a lack of enthusiasm) I'm seeing in our 2002 Jetta TDI (ALH engine with Garret VNT-15 turbocharger) may ...
4
votes
1answer
5k views

Engine misfires when car hasn't been driven for a couple of days

My 2001 Hyundai Elantra XD suffers from misfires during the first 5-10 minutes after starting the car. After this, the car runs as as it should. I'm not sure, but I think the misfires only happen when ...
5
votes
1answer
3k views

1998 Honda Civic - O2 sensor or catalyst failure?

I have the P0420 code on my 1998 Honda Civic DX (catalyst system efficiency below threshold bank 1). I want to be able to properly diagnose the problem myself without just throwing new parts at it. A ...
9
votes
2answers
1k views

R32 Skyline GT-R low power

EDIT: Added info from comments to bottom of question. My friend recently imported a right-hand drive 1990 Nissan Skyline GT-R (R32) with the RB26TT motor into the states. It's beautiful, and I'm ...
5
votes
2answers
1k views

Do I need to eliminate old gas before changing fuel injectors?

I have a truck with a full tank of gas (12-16 gallons?) that's been sitting for 12 months and I'm about to change the fuel injectors. The truck can barely make it around the block due to stalling out ...
3
votes
1answer
421 views

Should I replace my Catalytic converter?

My 2007 Xterra had the P0420 code pop on. My understanding is that it most likely that the Catalytic converter is going out. If this is the case, how high of a priority is it to fix? Before you ...
3
votes
2answers
222 views

Is my catalytic converter bad?

I have a 2006 Lexus LX 470 and I’m getting the check engine light on. I have a reader and I am seeing P0430 “ catalyst efficiency below normal (bank 2). I took some data from the sensors and plotted ...
2
votes
1answer
257 views

Auxiliary Shaft Sprocket

I have an '89 ford ranger that loses power and stutters intermittently around 2000 rpm. I thought this could be a timing issue. The Camshaft Sprocket and Crank pulley are lined up nicely but the oil ...
2
votes
1answer
153 views

Difference between banks for AFR & O2 sensor values

This is a well maintained 2007 Subaru with 140k km on the 3.0 litre six cylinder EZ30R engine. She's running a little scratchy most noticeable when cruising although no codes or anything. I decided ...

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