Motor Vehicle Maintenance & Repair Stack Exchange
Motor Vehicle Maintenance & Repair Stack Exchange

Questions tagged [cel]

An acronym for "Check Engine Light" warning light on a vehicle's dashboard.

The Check Engine light is an indicator lamp placed on the vehicle's dashboard. Typically amber or red coloured, this malfunction indicator lamp (MIL) indicates a problem with the computerized engine management system. It often has an icon in the shape on an engine.

Note that if it is flashing on and off this means that a misfire that will damage the catalytic converter is occurring. In this case the engine should be turned and repaired before being returned to service.

Also include tag for the specific Diagnostic Trouble Code (DTC), such as if available. Include tags for your make and model such as .

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What are good features to look for in an OBD-II reader

I recently took my car in for the engine light. It turned out to be a minor problem (crack in gas cap let water in). It would be nice to have a low-cost OBD-II reader to be able to find out for myself and either go to service immediately or delay…
Brian Carlton
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What possible causes for the "check engine" light can I check for myself?

The "Service Engine Soon" light came on yesterday and isn't going away on its own. The car drives fine, no weird noises, smells, or other symptoms. The manual is not very helpful, just directing me to take it to a professional for service. Before I…
Robert
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Why would a new gas cap cause the "check engine" light to shut off?

This happened to a friend of mine: The "check engine" light came on in his truck (Toyota). He replaced the gas cap and the light shut off. Then I also had a "check engine" light come on in my 1994 Chevy. I took it to the dealer, they hooked up to…
No Clutch
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Does waiting until the gas cap become faulty cause any damage?

The description for a fuel tank cap says: You can prevent unnecessary service costs by replacing the gas cap on modern vehicles before they go bad and the check engine light appears. Is this advertising baloney? Is there actually something that…
Calaf
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2005 Dodge Ram: Easy way to diagnose code P0420?

My truck is reporting a code P0420, which apparently is "Catalyst System Efficiency Below Threshold (Bank 1)" which can either be the catalytic converter or the rear O2 sensor. The code came on at about 30k miles, so I doubt it's the converter. So…
dave thieben
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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 said it could be a bad catalytic converter or…
endolith
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Sharp cornering is turning my Service light on for a second

Citroen C4 2005, Petrol Very rarely I happen to turn without braking properly and my forward momentum is quite high. In these situations I can feel the strain on my front wheels being very high. What happens occasionally is, my SERVICE light comes…
Иво Недев
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Why does the Check Engine code for emissions failure disable traction control and cruise?

I have a 2010 Forester with nearly 100k miles, and it just started giving the "emissions" check engine code (P0420, Catalytic Converter Efficiency Below Threshold). When that code is tripped in the system, it responds by flashing 'cruise' and…
Joe
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Does it make the most sense to replace an old car's entire exhaust system all at once?

Back story: The Check Engine light came on in my 2005 Chevrolet Malibu LS Sedan (V6 3.5L). I took the car to a mechanic #1 (M1), an independent shop. They replaced the EGR valve. A day later, the Check Engine light came on again. I took it back to…
Chris W. Rea
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'Check Engine' code P0171 System Too Lean - Is it safe to drive?

My 2003 Toyota Corolla's Check Engine Light came on. I read the codes using an OBD code reader and got P0171 - System Too Lean (Bank 1) and P0133 - 02 Circuit Slow Response (Bank 1, Sensor 1). The light is on solid, not blinking. From what I can…
culix
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How to Fix Check Engine Light (OBDII code: P0172)

I just saw the check engine light come on on my 2004 VW Passat B5.5 and did a bit of research. Some people said that it would be a faulty oxygen sensor. I was about to order one, but then I read this (from here): Next, looking at P0172, which is…
Max Goodridge
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why the check engine light on 75 mph speed?

My car is Toyota Corolla 2011. CEL lights at 75 mph. I pulled code p02757. There no other thing wrong. The car is running satisfactory, this check lamp is the only trouble.
abdul
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06 Solstice - weird hesitation / bogging under heavy throttle

I wonder what percentage of the questions here are from me about this car... When I try to accelerate with more than about 60-75% throttle at lower RPM (say, under 3k or so), the car starts to accelerate, then acts like there's a fuel cut. This will…
3Dave
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My BMW 325xi smells like gas

It is difficult to start my BMW it runs rough and smells like raw gas from the exhaust pipe. My check engine light is on. What could be the problem? I just had the engine replaced I am over 8,000 dollars into this car! There is about 89,000 miles…
Diane N
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How serious is the Engine System Service Required message on a Volvo V50 2007?

I got a 2007 Volvo V50 last week and the "Engine System Service Required" message has appeared. how serious is that message and can only a Volvo garage do the diagnostics? It has done 41000 miles. I have only driven it to work, around 180 miles over…
dsample
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