Idle & misfire Question check engine light

[femetal]

Ok I just bought a 2002 Jeep Liberty Sport 3.7 2wd.

The check eng light was on when test drove it. Lot said they would fix. I came back light was off and the shaking at idle was gone. I bought it. 2 days later the light came back.

This is what it does. turn jeep on its idle ruff check engine light blinks. The jeep will warm up then I turn it off and back on and the light stops blinking and stays solid but the idle is smooth and I have full power.

Had the check engine light looked at it sys its a misfire on #6. The lot said they replaced the coil pack the first time. They said to drive it 500 miles to see if it clears up if not they would put in a new injector.

They said they tested the compression and that it was good.

Any Ideas? Has anyone else had this problem?

 

[Hockeygoon]

Drive to autozone and have them pull the codes so you know what is going on instead of the lot telling you what they think is going on. If you have a question about the codes post them here.

How many miles?

Any idea when the plugs were last changed?

Brand and number on the plugs?

 

[vaksanov]

Not sure if you can do it on the 02 model but you can try turning the key off to ON 3 times without starting the car and it will show the codes on a speedo display. Also mine did the same after sitting for a month. I ran seafoam with the old gas and then added bg 44k cleaner with the new ethanol free gas. It seemed to help and clean out whatever was stuck in there. Seems like mine is picky so I've been putting shell primium since then and no problems other than being expensive on gas.