Ok. 99 ford expedition 4.6 I gutted out the coverters, then changed them out with new ones. No more random misfire codes. Also changed the spark plugs, wires, coil packs. Have all 4 o2 sensors (Bosch) not on yet. So now I'm getting codes P1124 TP sensor out of range and P0135 HO2S11 Heater Circuit Fault. What do I do?

171 Sys lean bank 1 possibly o2 sensor 300, cyl misfire detected random cyl. 302 misfire cyl # 2. 304 cyl misfire cyl #4 with all 3 of these codes it might be time for new spark plugs and wires

You need to install a new converter it needs the back pressure.

ENGINE MISFIRE

There are few possibilities that can cause engine misfire issues. It can be issue with spark plugs or faulty spark plugs. Also get the compression test done for cylinders. If any of cylinder shows low compression then required, then that particular cylinder will cause misfire.

Also get obd codes scanned, the error code will let you know which cylinder is misfiring or all cylinders are misfiring.

-----------

For your trouble shooting I suggest you to refer the help oinks below. It has step by step details for many engine misfire issues.

----------

Click the link below:-----

Ford Explorer Cylinder Misfire?

http://whoisbyme.blogspot.in/2012/06/ford-explorer-cylinder-misfire.html

---------

Engine Misfire codes on Chevrolet Malibu?

http://schematicsdiagram.blogspot.com/2011/12/engine-misfire-codes-on-chevrolet.html

---------

Cylinder 6 Misfire?

http://howtobyme.blogspot.com/2011/12/cylinder-6-misfire.html

------------

Misfire on cylinder 4?

http://schematicsdiagram.blogspot.com/2011/12/misfire-on-cylinder-4.html

-----

While stop engine idles like cylinder missing?

http://schematicsdiagram.blogspot.com/2012/01/while-stop-engine-idles-like-cylinder.html

----------

Ford Explorer 5.0L: Engine Miss?

http://whoisbyme.blogspot.in/2012/06/ford-explorer-50l-engine-miss.html

-----------

Oil on spark plugs and car misfires?

http://technoanswers.blogspot.in/2012/02/oil-on-spark-plugs-and-car-misfires.html

------------

Can cylinder misfire Damage the Catalytic converter?

http://schematicsdiagram.blogspot.in/2012/02/can-cylinder-misfire-damage-catalytic.html

------------

Car misfires and error code P0306 and P0303 is shown?

http://technoanswers.blogspot.com/2012/01/car-misfires-and-error-code-p0306-and.html

-----------

Chevrolet K1500 No spark, random misfire

http://repairhelpcenter.blogspot.com/2012/11/chevrolet-k1500-no-sparkrandom-misfire.html

-------------

2004 Ford F150: Engine Misfire and Lean Code?

http://whatisbyme.blogspot.in/2012/05/2004-ford-f150-engine-misfire-and-lean.html

-----------

1995 Toyota LS: Misfire at idle or low RPM

http://whatisbyme.blogspot.in/2012/04/1995-toyota-ls-misfire-at-idle-or-low.html

--------------

Toyota Corolla: Random Misfire?

http://technoanswers.blogspot.in/2012/04/toyota-corolla-random-misfire.html

----------

2006 Ford Freestar: Misfire on Cylinder Number 2?

http://whatisbyme.blogspot.in/2012/06/2006-ford-freestar-misfire-on-cylinder.html

-----------------------------

This will help.

Thanks.

its faulty coil.

Get the compression test done on each coil.these will let you know if its faulty coil or not.

=========

It can be issue with spark plugs or faulty spark plugs. Also get the compression test done for cylinders. If any of cylinder shows low compression then required, then that particular cylinder will cause misfire.

Also get obd codes scanned, the error code will let you know which cylinder is misfiring or all cylinders are misfiring.

-----------

For your trouble shooting I suggest you to refer the help oinks below. It has step by step details for many engine misfire issues.

----------

Click the link below:-----

Ford Explorer Cylinder Misfire?

http://whoisbyme.blogspot.in/2012/06/ford-explorer-cylinder-misfire.html

---------

Engine Misfire codes on Chevrolet Malibu?

http://schematicsdiagram.blogspot.com/2011/12/engine-misfire-codes-on-chevrolet.html

---------

Cylinder 6 Misfire?

http://howtobyme.blogspot.com/2011/12/cylinder-6-misfire.html

------------

Misfire on cylinder 4?

http://schematicsdiagram.blogspot.com/2011/12/misfire-on-cylinder-4.html

-----

While stop engine idles like cylinder missing?

http://schematicsdiagram.blogspot.com/2012/01/while-stop-engine-idles-like-cylinder.html

----------

Ford Explorer 5.0L: Engine Miss?

http://whoisbyme.blogspot.in/2012/06/ford-explorer-50l-engine-miss.html

-----------

Oil on spark plugs and car misfires?

http://technoanswers.blogspot.in/2012/02/oil-on-spark-plugs-and-car-misfires.html

------------

Can cylinder misfire Damage the Catalytic converter?

http://schematicsdiagram.blogspot.in/2012/02/can-cylinder-misfire-damage-catalytic.html

------------

Car misfires and error code P0306 and P0303 is shown?

http://technoanswers.blogspot.com/2012/01/car-misfires-and-error-code-p0306-and.html

-----------

Chevrolet K1500 No spark, random misfire

http://repairhelpcenter.blogspot.com/2012/11/chevrolet-k1500-no-sparkrandom-misfire.html

-------------

2004 Ford F150: Engine Misfire and Lean Code?

http://whatisbyme.blogspot.in/2012/05/2004-ford-f150-engine-misfire-and-lean.html

-----------

1995 Toyota LS: Misfire at idle or low RPM

http://whatisbyme.blogspot.in/2012/04/1995-toyota-ls-misfire-at-idle-or-low.html

--------------

Toyota Corolla: Random Misfire?

http://technoanswers.blogspot.in/2012/04/toyota-corolla-random-misfire.html

----------

2006 Ford Freestar: Misfire on Cylinder Number 2?

http://whatisbyme.blogspot.in/2012/06/2006-ford-freestar-misfire-on-cylinder.html

-----------------------------

This will help.

Thanks.

There are few possibilities that can cause engine misfire issues. It can be issue with spark plugs or faulty spark plugs. Also get the compression test done for cylinders. If any of cylinder shows low compression then required, then that particular cylinder will cause misfire.

Also get obd codes scanned, the error code will let you know which cylinder is misfiring or all cylinders are misfiring.

-----------

For your trouble shooting I suggest you to refer the help oinks below. It has step by step details for many engine misfire issues.

----------

Click the link below:-----

Ford Explorer Cylinder Misfire?

http://whoisbyme.blogspot.in/2012/06/ford-explorer-cylinder-misfire.html

---------

Engine Misfire codes on Chevrolet Malibu?

http://schematicsdiagram.blogspot.com/2011/12/engine-misfire-codes-on-chevrolet.html

---------

Cylinder 6 Misfire?

http://howtobyme.blogspot.com/2011/12/cylinder-6-misfire.html

------------

Misfire on cylinder 4?

http://schematicsdiagram.blogspot.com/2011/12/misfire-on-cylinder-4.html

-----

While stop engine idles like cylinder missing?

http://schematicsdiagram.blogspot.com/2012/01/while-stop-engine-idles-like-cylinder.html

----------

Ford Explorer 5.0L: Engine Miss?

http://whoisbyme.blogspot.in/2012/06/ford-explorer-50l-engine-miss.html

-----------

Oil on spark plugs and car misfires?

http://technoanswers.blogspot.in/2012/02/oil-on-spark-plugs-and-car-misfires.html

------------

Can cylinder misfire Damage the Catalytic converter?

http://schematicsdiagram.blogspot.in/2012/02/can-cylinder-misfire-damage-catalytic.html

------------

Car misfires and error code P0306 and P0303 is shown?

http://technoanswers.blogspot.com/2012/01/car-misfires-and-error-code-p0306-and.html

-----------

Chevrolet K1500 No spark, random misfire

http://repairhelpcenter.blogspot.com/2012/11/chevrolet-k1500-no-sparkrandom-misfire.html

-------------

2004 Ford F150: Engine Misfire and Lean Code?

http://whatisbyme.blogspot.in/2012/05/2004-ford-f150-engine-misfire-and-lean.html

-----------

1995 Toyota LS: Misfire at idle or low RPM

http://whatisbyme.blogspot.in/2012/04/1995-toyota-ls-misfire-at-idle-or-low.html

--------------

Toyota Corolla: Random Misfire?

http://technoanswers.blogspot.in/2012/04/toyota-corolla-random-misfire.html

----------

2006 Ford Freestar: Misfire on Cylinder Number 2?

http://whatisbyme.blogspot.in/2012/06/2006-ford-freestar-misfire-on-cylinder.html

-----------------------------

This will help.

Thanks.

I had the same issue on my 03 Expedition. Jerks randomly but gets worst and extreme misfires/stalls/shuts down. Then restart and its fine. These bucks more likely are random misfires (Chk engine light may/not come on) associated with the ignition coil/s failing. These coils have a average life expectancy of 79,000 miles or 5yrs. I replaced all 8 COPs (coil over plug) @ 48,000 miles just to be safe with new accel coils. The coil models for engines 4.6/5.4 V8s are DG508. Hopefully this helps!

P0316 .... Engine Misfire Detected on Start-up (first 1000 Revolutions)

P0300b .. Random/Multiple Cylinder Misfire Detected

P0304b .. Cylinder 4 Misfire Detected

P0357 .. Ignition Coil G Primary/Secondary Circuit

P0353 .. Ignition Coil C Primary/Secondary Circuit

From codes you need new spark plus, Ignition Wires, and ignition coils

replace crankshaft senor, its bad, faulty. Check your O2 sensor. change fuel fuel filter and spark plugs and wires with new ones.

My was doing the same thing, it was an EGR valve and a misfire on the #2 cylinder which required a new spark plug and a coil pack
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8mm