What's wrong?
 

I got codes

P 0300- Random/multiple cyl misfires
P 0302- #2 misfire
P 0303- #3 misfire
P 0158- o2 sensor circuit high voltage bank 2 sensor 2
P 0305- #5 misfire
P 0306- #6 misfire
P 0307- #7 misfire
P 0838- 4wd switch circuit low
P 0837- 4wd switch circuit range/performance

Have an 02 Grand Cherokee with the V8. The engine light comes on randomly and goes off, sometimes staying on longer than other times. A few days ago it started flashing when accelerating on the highway and wouldn't go above 45-50 mph. Let off the accelerator for a few seconds and started accelerating again slowly and it was fine. This has happend about 4 times in the last week now. Anyone know what could be wrong?

Thanks,

Eric

With all the misfires I would check dist. Thats where I would start. Check all your plugs and make sure your getting fire.

Thanks, I will take a look at the distributor. It's funny. The engine light hasn't came on at all after I posted this. I will check the codes again tomorrow and see if anything changed.

Alright, I was out of town for the last couple months and got home about a week ago. I took a look and found that the motor had either a cracked head or block. I used a new product from Bars Leak called Head Gasket Fix. You add it right to the antifreeze and don't have to drain anything. Something with the high temp. and the product forming a gasket that's suppose to be stronger than a reg gasket. I added that and changed the oil with valvoline max life and now there is no antifreeze leaking into the motor. There is a tick which I believe to be a stuck lifter more than likely and will be looking into that this week.

I'm going to be changing plugs, they are more than likely fouled from the antifreeze at the same time that I take the valve covers off to fix the lifter.

The main problem that remains is that there seems to be something wrong with the shifting and power of the motor. In the codes I got might suggest the 4wd switch, could this be causing it? When i hit the gas and it goes to overdrive the vehicle won't go any faster, and most of the time slow down to about 30, and the check engine light flashes, which from what I've read has to do with the catalytic converter. I am also assuming the o2 sensor is shot from the antifreeze getting in with the oil so I will have to replace that too.

Anyone have any ideas?


Eric