I've got a 96 Dodge Avenger with 2.0. Error Code P0300 Misfire on Multiple Cylinders. Misfires on idle with AC on and with or without AC on acceleration. I noticed the exhaust is blue and smells rich. I've replaced the plugs, Ignition coil, checked the PCV Valve, Ohm'd the plug wires and all checks good. I also put in fuel injector cleaner on last fill. Could it be EGR Valve? Not sure what else to check!

 

When you pulled the plugs did they have oil on them???

If they did then your plugs are grounding out and not firing. This is caused from the valve cover gasket leaking into the holes that the spark plugs go down. There is a gasket that goes on the outside and then little circles that go around the holes. Check and make sure that there isn't any oil in there. If there is change the valve cover gaskets. If not then you might have to get it checked by a mechanic.

Also when I had a 95 avenger 4cyl my car's EGR valve was completely removed and blocked off so I can vouch that if the EGR isn't working correctly that it shouldn't cause a misfire.

On another note an EGR valve not working correctly or being absent will make you get slightly less MPG. Have you noticed a significant drop in MPG as in 10 MPG less???

If you have an injector might be stuck open. I had 2 short circuit and stay open on the V6 I have and I was getting close to 2MPG instead of 26MPG. Since yours is an I4 the injectors should be slightly smaller and if 1 injector is stuck open or isnt closing completely that could cause the richness in the exhaust. Many people can also confuse Fuel smoke as oil smoke or a headgasket failure just FYI.

 

The plugs had no oil on them and I ohm'd the injectors and listened to them with a screwdriver and seem to be working properly. The only oil leak on the valve cover is by the camshaft position sensor. The plugs I replaced looked good, I just replaced them because I was told this engine does not like platmun which I put in a year ago.

 

could be a stuck injector

 

Wouldn't that cause a misfire on one cylinder not multiple?

 

You can have one stuck and it's dumping sooo much gas and not firing properly that it can cause others to misfire as the one cylinder didn't fire and causes a hiccup

 

ummmm......

Look under the hood. I know on the 2.5L it actually says on the car to use platinum plugs....

On the 2.5 it says 60,000 Miles for regular plugs and 100,000 miles for platinum...

But anyway what badvenge said....

 

Is 54psi too high for the fuel pump off the port from rail? Repair manual says 47 - 50psi.

 

I wouldn't think 4 psi would be that excessive

 

I brought in for diagnosis and they were able to pull another code and said to change the TPS and clean the code and if that does not fix the problem then the O2 sensor. Ended up changing both and putting a bottle of Seafoam in the gas tank and still no fix. Any other ideas before a bring it back in for a more indepth diagnosis?