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Focus Preacher
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Discussion Starter #1
Hi,

It's been a long time but anyway i've replaced the girlfriend MK1.5 D2.0 spark plugs with BOSCH Iridium Platinum Fusion (4 ground electrode model) bought from rockauto.

She experienced hesitation at high speed and MIL/CEL is now on. Of course I got the dreaded P0300 code with P0301. I though it was the COP since the boots where stuck badly and I had doubt I damaged them. I ordered 4 new COP oem Motorcraft. Still has hesitation but with P0300,301 and 304 now.

Is it possible bad spark plug? First time I use something else than Motorcraft Iridium.

Coils are new and OEM cost me an arm and leg.
 

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Those spark plugs are absolutely trash and they are causing your problem. I know I made that mistake once. If you change the spark plugs out and you get a new problem it's the spark plugs. Just throw on some simple Autolite spark plugs, or Motorcraft spark plugs.

Sent from my LG-LS997 using Tapatalk
 

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Rule #1 of spark plugs...............the more electrode tips you have above the OEM number that came on the car the MORE TROUBLE you will likely have. Nobody ever tells you this but more electrodes require more heating, the jump off points become more remote from each other and the localized hotspots then disappear to require some of your spark energy to reheat the jump off point enough to ionize the air to make the air circuit. Plus 4 type tips are similar to surface gap plugs, they tend to run cooler and that tilts your heat range to give trouble. Also why the much vaunted E3 spark plugs are such utter trash. Again, too much metal in too many places.

My view only and you will never find that in any book I know of, but since coming up with the idea I have never seen any information to break the idea yet.

In short, the multiple tips sap your spark energy to lower the voltage at the plug firing.
 
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Save the Bosch spark plugs for a German car, where they belong.... Put the proper plugs in and you'll avoid most spark plug related problems.
 
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X2, any car that uses them already has a coil intended to fire that type of plug.
 
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Focus Preacher
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Discussion Starter #6
Wow ok thanks guys.

The fact they where recommended by RockAuto and their best selling spark plug for the MK1 with duratec is rather disturbing!

My mistake to follow them!
 

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Vendor
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Wow ok thanks guys.

The fact they where recommended by RockAuto and their best selling spark plug for the MK1 with duratec is rather disturbing!

My mistake to follow them!
Hello ELCouz,
Sorry to hear that the plugs did not work out for you.
The recommendation you speak of (assuming you are referencing the heart symbols in the catalog), represent parts that are ordered most frequently for an application (with fewest returns). For a category like spark plugs, it is not uncommon to see one or more of the heart symbols for each type of plug (copper, iridium, platinum, etc.)
 

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Use Denso it20's.......
 

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How do all you people have so much trouble with Bosch O2 sensors? Have them on everything I got and they run perfectly and for years. We are aware that Bosch was the creator of the original O2 technology right?
 

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How do all you people have so much trouble with Bosch O2 sensors? Have them on everything I got and they run perfectly and for years. We are aware that Bosch was the creator of the original O2 technology right?
I ordered a Bosch O2 sensor online that said it was for my Chrysler. It was actually a universal with a plug that you had to crimp connect a pigtail to. No solder of course. I found that to be pretty rinky dink. Worked fine for about a month, then started throwing codes about an O2 heater malfunction. Wire connections checked out. The Chrysler forum I was on had a number of complaints about the Bosch units. I put an OEM one in and it worked fine until I got rid of the car at 240k.

Yeah, I’m aware of who Bosch is. That’s why the first one I bought was a Bosch. Their history doesn’t mean squat to me if I can’t pass emissions.
 

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Rule #1 with O2 sensors is to NEVER buy a universal one, the self-crimp connections will KILL you. O2's are very low volt units and ANYTHING wrong with the connection and they simply don't work right. The resistance can go up so little you think the connections are fine and they would be--for 12 volt, but at the low volt/amp there they are NOT. And, if the wiring showed good then you could have easily powered up the heater to see if it worked or not in seconds to then see if it was heater or connection trouble.

Like I say..............a long stream of Fords with Bosch O2's, and zero issues and never any trouble at all.
 
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