2004 ford ranger missing badly...

[nh2123]

Hey Ranger Station,

I put a can of seafoam through the fuel tank and my mpg went down from 25 to 19 highway miles and stayed there for 3 tanks. Did some research and decided to replace pcv valve, fuel filter, plugs, and both o2 sensors. (wires were on back order). I disconnected negative battery terminal to reset the computer. After this the truck ran alot better for around a tank and a half and mpg went up to 22. Then the wires came in and I installed them as well as cleaning the mass airflow sensor, cleaning the throttle body, and replacing the air filter. Truck ran good for 100 miles and then started missing very badly to the point that it would only drive at above 3000 rpms. Hooked up odbii and had codes for cylinder misfires (3 codes: 1 for cylinder 2, 1 for 3, and 1 for multiple) as well as a code for bank 1 sensor 1 (o2 sensor) sending lean signal. I realized that I had hooked the wires from the coil to the plugs up in the incorrect order. I fixed that and still bad misfires. I tried taking the new plugs out and checked them for damage, cleaned them (some carbon on them) and checked the gaps. Reinstalled them and still missing badly. Took the new wires off and tried the old wires. Still misfires. Tried switching out the coil pack. No luck. Tried taking out the new plugs and putting the old plugs back in. Still misfiring. Could a lemon o2 sensor be causing such severe misfires? Could it be the pcv valve? Or the fuel filter. Thought it was less likely the fuel filter or pcv valve since i got no codes for them. I need some expert help here. Seems I have done all I can. Thanks for your time, Mike.

 

[nh2123]

No one?

 

[adsm08]

The 3 misfires are causing the lean code.

I have seen rare cases in Fords where the computer sees a misfire so severe that it shuts down fuel injectors and won't fire them again until it is cleared out.

Get your wires and coil on and in the right order. Reset the computer again and see if that helps. That is where I would start.

 

[Norrick]

My engine blew a hole in the intake manifold and was misfiring like crazy and the computer was throwing lean codes in addition to misfires. There was a hissing sound present that wasn't there before and if you spray a flammable cleaner under the hood the idle would kick up momentarily (I used brake cleaner to discover the vacuum leak).

 

[shane96ranger]

Sometimes plugs can have cracks in the ceramic that you can't see. Did you by chance have them shipped via UPS, where the delivery man may have recreated the scene from Ace Ventura?

 

[54inches]

This is the exact problem that I have. SEARCH saves me again!

 

[54inches]

OK, well, I unhooked the battery overnight and nothing.

I went to work and it was worse and finally threw another CODE.

I unhooked the battery at work.

Nothing better after work.

I went to the parts store and grabbed a coil on a whim.

When I got home, I noticed the CATS were RED HOT, which definitely meant it was missing.

Changed the coil and it runs like new.