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2002 jeep liberty 3.7 my baby's car (flashing check engine light)

recently, about 200 miles ago, I changed the spark plugs

coming back home the check engine light comes on flashing. I checked the manual and I need to get the catalytic converter checked but my friend used a scanner to get a code and we only got one po304 misfire clynd#4

I replaced all the spark plugs again

1#clean 2#black

4#wet 3#black

6#black 5#black

and new

*crankshaft position sensor

*smell of gas while runs

*now only cranks but won’t start

do you have any solutions or ideas for this problem??

how would I know if the catalytic converter needs to be replaced?

You’re going to need to make it past the spark plugs to other ignition problems, but you very well may have other problems as well. The black plugs all indicate you’re running rich as does maybe the smell of gas. The wet #4 indicates it isn’t firing (and makes sense of the code). The signs of rich running could come from ignition problems but also any number of other things. Since its been cranking w/ no start have you at least looked for spark?

I have no clue as to why you are mentioning the cat conv.

And don’t drive a vehicle if the CEL in blinking.

If you say something about other maintenance items people might be able to help more. How is the air/fuel filter? You mention plugs but not wires? Other ignition system components? Etc.

have no clue as to why you are mentioning the cat conv.

Well if it is running that rich, the OP is going to need one if he continues to drive it, if it is not all ready too late.

I mentioned the cat conv b/c the manual states that as a possible problem if the CEL is blinking. I haven’t driven it since but did try turning it on after changing/checking a few things. It did turn on the next day with a lot of gas smell and trembling, I pushed on the gas and the trembling stopped. There weren’t any other noises or anything else I could hear that was wrong with it.
I know the problems that come with cat conv damage include things such as misfire, crank and no start, power loss (which did happen the day of the original incident).
I’m tired of guessing and don’t want to mess it up any more than it already is or spend more money on things that aren’t the problem.
I don’t have a scanner and am unable to move it at the moment.

  1. After a few tries/cranks, the car will start but dies right away
  2. air filter is new
  3. will check fuel filter shortly - but could this really cause these problems?
  4. what about the wires? it’s on a harness
  5. what do you mean by “other system components”?


It’s easy to disconnect, or forget to reconnect, the electrical plug for the MAF (Mass Air Flow) sensor in the intake tube. A disconnected MAF will allow start up, and then, stall.
Things that can cause the engine to run rich are a faulty reading engine coolant temperature sensor, a thermostat hung open, radiator cooling fan running when the engine is cool.

If you were having a problem w/ the cat bad enough to set the light to blinking you’d probably have gotten a related code. The most common thing that sets the cel to blinking is a misfire - which is what you got - a cylinder 4 misfire and lo & behold you got a gas soaked # 4 plug.

It looks to me like the most likely problem is ignition. The plugs are obviously not it as you have replaced them. You should also replace the wires. Then the “other components” depend on what kind of ignition system you have (I don’t know the Jeeps) - it may mean an ignition coil or distributor and coil.

Check this out:

Did you install the factory recommended plugs?? Did you disturb or disconnect any other components when you were changing the plugs? Did you damage (the rather fragile) wires when you removed them from the plugs?

ok guys i’m back i recheck all the electrical plugs also clean the spark plugs once again i get Bosch Spark Plug Platinum
i think maybe is one of the coil + something also i need to wait to scan the computer to get another code

i need to wait to scan the computer to get another code

Why do you need to wait? Even if the light is off, it likely will still have the code unless it was reset. Some auto part stores will read the codes for free. We will have a lot more information to go on if we know the code. Note: the code(s) should be in the form [P0123] post back the actual code not just the English translation.

I am leaning towards a coil problem.

The check engine light has to be erased, and, then, the car driven, and the computer scanned for trouble codes. Older cars’ trouble codes can be erased by disconnecting the battery for a few minuets. Your Jeep? Dunno.
The #4 fuel injector may be stuck open. That would flood #4 cylinder. To see if the fuel injector is at fault, you can swap #4 fuel injector. Run the engine, and see if the trouble code moved to the other cylinder. If it moved, the fuel injector is bad.

i need to wait because i don’t have scanner
my friend from santa rosa one hour from my house he have one
but hes is too busy

that’s the razon i have to wait

yes i disconnected the battery and erased the code, then i let the engine run for 10min. or less don’t remember but after i turned it off, it doesn’t want to start. will start for ~2 - 3 seconds then dies. in those few seconds I can clearly hear noise, like puttering air.
I bought a scanner & it didn’t give me an error code, although it did flash monitor oxygen sensor and catalytic converter (both).
I have a feeling it’s either the cc or the muffler. in the past I’ve had a similar problem, except that that was a 4 cylinder and this is a v6
and the problem was the muffler this was after i had spend more of $150 on labor and cataly replaced

does anyone know if it’s possible to test the actual catalytic converter, oxygen sensor, or muffler, to know if they’re working properly before replacing them? I have removed the cc, can I take it to a shop or somewhere to get tested, since the car won’t stay on.