I would just use what works. I think Autolites are fine spark plugs should be no problem. I would be careful with seafoam I'm not a big fan of that stuff. I think it does more harm than good. If you read the ingredients you will see what I mean. Just my opinion, there are lots of people on here that swear by it but, I'm not one of them.

 

Seafoam is the Greatest!! I put a can of Seafoam in my tank every 3-5 months depending on how much I drive. I notice a big improvement every time I use it. I wouldn't over use it tho. That can be bad for your engine and fuel system.

 

I wouldnt run NGK plugs in anything , you are fine with the Autolites , If you run it hard a lot I would do the 103 or the AR103

If they still make the AR103 hands down I would run that plug

Tom

 

summit racing sells the AR103s.

Are the AR103s really worth the extra money compared to the regular 103s?

 

There is a great "stickied thread" on sparkplugs for the Dtec.

 

I think my Focus has those plugs. Was yours a rental car by chance? The uneven idle comes and goes. I have a strong suspicion it's related to fuel quality (most likely the amount of ethanol in the mix) but I have no real way of confirming this due to the lack of "name brand" gasoline around here. Otherwise, if the issue went away with different plugs I would say that was the issue and wouldn't go back.

 

Picked up some 103s today while getting some plastic clips from autozone. Gapped at .060 and threw them in.

Idle is much smoother now. Haven't really noticed a power increase but ive only driven 3 miles with them so far. Car has 67,000 miles.

 

I was doing some work on the car my 09 and at 75,000 i thought why not change my plugs, I used the Bosh platinum 2 now I have a code 2 days later saying random misfire,[thumbd] any thoughts??

 

never use Bosch on ford you will always get a misfire. ive had 4 ford tried Bosch in all of them and all misfire. Got AC delco never had a problem

 

Ran AC plugs for 2 years, car ran great. Yesterday #1 & #2 boots failed. Misfire with flashing engine light. I was too far from home to drive home and replace parts myself.

Local shop replaced 4 boots and spark plugs with Autolite AP104[ffrocks]. The mechanic blamed the failed boots on AC plugs.

What I would like to know is what is "tune electronic ignition minor?" That is one of the services listed on the invoice.

 

Use whatever is in the owners manual? I did the Motorcraft ones. They're fine.

If you have Autolites in there now and it runs fine, seems best to let it be.

 

Thanks I will go to the ac. send the bosch back

 

Replacing the boots & plugs

 

Bosch makes the ignition coils ...

 

Bosch makes a lot of things. Some are good, some are bad.

I've got Autolite 103s and I would not use anything else.

 

I have 104s in... the guy at FSWerks said I should go with 104s instead of 103s not sure why. Perhaps because I'm not modded heavily?

The 104s definitely made a difference but it's not a surprise from what the old one's looked like when I took them out on Tuesday.

 

I been running 103s since about 30k, just replaced them at 55k, the car runs great, I remember the day i switched to them, i dont know if it made a difference on the high rpm part, but It seems a little better on the low end. I have a manual so i can notice it a bit when taking off

 

I run 104's without any issues. Been about 10K now and about 20 shots of nitrous.

 

Bosch multi ground electrode plugs only work on NON DIS engines.

 

Just gonna throw my experience into the mix here as well.

Tried the Autolite 103s and had issues with bogging under WOT from a complete stop. Almost sounded like I was flooding the cylinders with fuel, like it was too rich. The only mods to the engine are the FSWerks CAI and race exhaust. I didn't see them as being likely culprits.

Swapped the OE plugs back in for the winter and replaced them with Autolite 104s several weeks ago. So far no issues with WOT from a stop and power is a'plenty.

The 104s came just in time as well. Here's what the OE's looked like at roughly 64k miles.

 

Did you gap the 103s before you put them in?

 

Yes. To .050 inches. The shop manual gives an acceptable range of .048 to .053 for the 2008-2009

 

If the 104 worked good the 103 would of as well , there is no way that 1 heat range would cause any driveability issues you you would see or feal

Colder plug will just not keep the oil / carbon burned off and will need replacing sooner , you had other issues somewhere

Tom

 

I gap my 103 to 0.055 and haven't had a single issue.