[Craftwise]

I was hoping to get some help and advice about my 2010 Ford Taurus Limited AWD 3.5L car. The other week it began running rough; wobbling in park and worse in reverse and then shuddering when going over 40 mph. The check engine light came on and I took it to Autozone to use a diagnostic reader. I got P0302 Cylinder 2 Misfire detected and P0202 Injector Circuit Open Cylinder 2 on the readout.

Naturally, I replaced all of the spark plugs and ignition coils. I also replaced the battery because it was four years old. It ran fine for maybe 20 miles and the check engine light came back on and it began shuddering again. I ran another diagnostic and got only P0202 Injector Circuit Open Cylinder 2 as the readout. So I replaced the fuel injector I believe is #2 (bottom left on engine when facing it) as per a firing order diagram I found online (Autozone couldn't locate a diagram for me) and I replaced the fuel injector wiring connector (pigtail) for the injector as well. I hooked up the battery and about 20 miles later I'm having the same problem with shuddering and the check engine light back on.

Does anyone have any idea what the problem could be? I can't afford a mechanic currently and would rather fix the problem myself if at all possible This is my only vehicle for work and the kids. Any help or advice would be so greatly appreciated! Thank you!

 

[Craftwise]

I should mention that it drives just fine after taking the battery off for over ten minutes and then hooking it back up again. No shuddering or wobbling in reverse or going over 40 mph. After driving for a while the check engine light comes back on and it begins shuddering and running rough again. I'm awfully perplexed.

 

[Jeff K]

Have you checked the #2 injector (middle one on firewall bank) to be sure its electrical plug is secure, tight and corrosion free? Have you checked the #2 injector harness for damage, melting, etc?

 

[Craftwise]

I did replace what I thought was injector 2 and the harness. Front left injector on a V6.

 

[Craftwise]

Is there a good place to find the firing order?

 

[Jeff K]

Unless Ford changed the way they number cylinders with the Cyclone, #1 is the pass side firewall cyl, followed by #2 center cyl firewall side, #3 driver side firewall, Front bank pass side is #4, front bank center is #5, driver side front bank is #6. Ford numbers their cylinders differently than GM. which alternates numbers between the banks on V type engines.

 

[terbob3]

Try this...............

 

[Craftwise]

I think I replaced the wrong injector and harness. Both online and the parts store told me it was the bottom left (on the front radiator side). If it's the middle back, firewall side I will replace that this weekend.

 

[Jeff K]

NEVER trust any "diagnosis" from the counter person at any parts store! 99.5% of the counter people no NOTHING about cars or diagnosing issues.... all they know is how to punch numbers into the computer and (hopefully) get you the right part.

Example I have seen happen to a former coworker: Coworker takes car to parts parts store because CEL is on. P0171 and 174 come up when coworker has codes read at parts store. Counter person, who knows identically zero about cars, sells them two O2 sensors since the codes are O2 codes. CEL still on after "repair" because the real problem is a vacuum leak from a disconnected vac hose it took me 2 minutes to find after I popped their hood. Of course, electrical parts are NO RETURNS. Car owner was out $80+ for O2 sensors they did not need.