Skip the auto shop - Our mechanics make house calls

Q: If cylinder 3 misfires is that a bad thing?

asked by on

I brought this car to get a diagnostic test. It stated that cylinder 3 misfired and that the catalyst is damaging. Is this bad and expensive?
My car has an automatic transmission.

A: Hi there. A misfiring cylinder can be expen...

Hi there. A misfiring cylinder can be expensive if allowed to continue. The catalytic converter can be damaged. If the cylinder is misfiring, the coil, wire, and/or spark plug could be the cause. First swap the spark plug between cylinder 3 and one of the other cylinders. Make sure to note which ones you swapped. Check to see if the misfire moves from cylinder 3 to the other cylinder. If this is the case, then replace the spark plugs as the swapped plug is at fault.

If there is no change, then the wire or coil may be at fault. Wire and coil resistance can be checked with a digital volt/ohm meter and compared to specifications. If you would like to have a professional take a look, a certified technician from YourMechanic can come to your car’s location to diagnose the misfire and follow through with appropriate repairs.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: What else can i do to diagnose the exact problem of my cars miss fire on the 3rd cylinder?

If electronics and fuel supply have been ruled out, the next possible cause is a mechanical issue. Have a compression test done across all 4 cylinders. If #3 is lower than the other three cylinders, it is possible there is...

Q: Ticking sound on drivers side

Deficiencies of various types can cause lifter and valve train noise, including ticking noises. The bottom line is if the ticking noise did not exist at all prior to their work on the valve train, but occurred immediately at the...

Q: I stomped my gas and it backfired out of the tail pipe

Hello. Backfiring can be caused by many things. A few common causes are low quality fuel or problems with the fuel, ignition issues, or a problem within engine management systems. If the vehicle is filled with low quality fuel, it...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...