4th cylinder misfiring

replace fuel filter, air filter, spark plugs, wires, distributor cap /rotor, if you have one. new oil with your filter ? just thought I'd ask, have a auto parts store pull code to see why your service engine soon light is on. this will tell you what sensor needs replaced, I'll bet its the oxygen sensor !

Use silicone grease on the boots.

Thats exactly what it sounds like.

• If you can please list the code that was read and also the symptoms for me I may be able to give more specifics on the code itself. As for a misfire in any cylinder I will lists some things that are indicative of this.

1. Spark Bad fuel injector
2. plug
3. Plug wire
4. Coil
5. bad 02 sensor
6. bad computer.
7. out of gas
8. bad catalytic computer
9. burned exhaust valve
10. poor compression.

• Symptoms can be a hard to start engine.
• Hesitation or bucking when accelerating.

• A rotten egg smell from the exhaust can indicate a bad Catalytic Converter.
• If it has been a long time since a tune up then plugs and wires may be in order.

Hope this helps and thank you for using FixYa.

Regards, Tony

Hi It sounds like the engine management system has detected a fault. I`m assuming its a petrol engine and the most common problem is one of the coils has gone.
To find the exact fault the car needs to have a diagnostic check which will tell you which coil or other component has malfunctioned.
Good luck i`m sure it won`t be a big problem
John ( South Wales UK )

A blinking check engine light is a signal that a damaging misfire is occurring in one or more cylinders. Your car is shaking because of the uneven power loss between firing cylinders and those that are misfiring. If you take your car to a major auto parts store, they will read out the stored trouble codes in your car's computer memory--and they'll do it for free. These codes will tell you which cylinders are misfiring and will help you find out why. Do it soon before more engine damage occurs--$$$$.

The first thing you need to do is scann the codes for the check engine light, the computer is always watching all systems when it sees a problem it stores a code with the problem and turn on the check engine light, for example in could have a code that reads po301 cylinder 1 misfire, you would then know cylinder 1 is misfiring and then with somw testing see why its misfiring. there are many auto part stores that will scan the codes for free and give you a print out with the codes, if you get the codes i can help you better. the charging gauge you will need to have the alternator checked to make sure its not over charging, if it is then that would turn the light on, good luck.

Replaced the MAF sensor - nothing. Took it to a authorized toyota shop & checked compression which check out good and put the computer on. Computer read mis-fire on cylinder 1, and then multiple misfire (like it would jump around). We went ahead and replaced the fuel injector on cylnder 1 - did not solve problem as when we hook the computer up, misfire seemed tp stay at idle and seem better when running high RMP, but check engine light is on as it never went away. Went ahead and replaced the coil pack to cylinder 1 - nothing. what am i missing?

Instead of the auto-zone trip , take it to the dealer !

See if your car has an ignition control module. They will go bad over time and cause random engine misfiring. Just went thru it with my 2002 Buick LeSabre. 120,000 miles on the engine. Replaced plugs, plug wires and check the coils. It was the ICM.