I have a 2013 Ford C-Max Energi (US-California) with about 150kmi, mostly highway commute miles, great shape overall.

We get an injector 3 code maybe once every six weeks. We put in a bottle of STP Injector Cleaner and it goes away (until next time).

I was a professional mechanic back in the day and am comfortable doing the needful for a more durable repair, but could use some guidance on likely best approach since my experience goes back a couple decades ago.

My plan is below, I'd appreciate any critique and I guess my main question is how to get the new calibration code into the onboard computer (ECM?) after replacing the injector, assuming that turns out to be necessary.

I'm thinking a two-phase approach is called for:

Step 1:

  1. Obtain the proper seals needed for a single injector R&R.

  2. Remove injector 3 (still working out which one that is, I understand they're not numbered by the cylinder they serve).

  3. Clean injector with my hand-pump Bosch injector cleaner using injector pulser to open the valve and mineral spirits in the injector cleaner. This injector cleaner was originally designed for Bosch CIS injectors (MBZ, VW, etc.) but I think will do the job.

  4. Inspect spray pattern and valve sealing/leakage to inform possible replacement.

  5. Replace injector using new seals. Do this even if injector fails inspection so I can get my wife back on the road while I wait a week or so for a new injector.

It that works, that's the end of a happy story. If not, proceed to:

Step 2:

  1. Obtain replacement injector and seals.

  2. Repeat R&R using new injector.

  3. Figure out how to get the (different/new) calibration code for the new injector into the Ford ECM or wherever it goes.

  • I've also got a 2013 C-Max Energi (about 93,000 miles) that has started getting injector codes this year. It's now in the shop getting all injectors replaced as part of a FordESP warranty (just in time...the warranty will expire at 100K miles). We'll see if the code stays gone.
    – Bob
    Jan 2, 2020 at 7:01

1 Answer 1


Okay, after further research and since there have been no other replies, I'll post what I've found:

  • Using a CIS-style injector pump here is okay (as long as you watch the pressure) but is unlikely to do a thorough job of cleaning by itself. For that you need ultrasonic cleaning. This is shown in quite a few YouTube videos. Basically you pulse the injector (continuously) while the nozzle is submerged in an ultrasonic bath. Cleaning solution specs are sparse, but something like Simple Green or dilute Purple Power seems to be the idea.

  • You can't remove just one injector. Either all the fuel-rail o-ring seals are separated or all the injector seals are separated. So minimally you need four bottom and one top seal or four top and one bottom seal. Probably best to just figure on a whole set of seals top and bottom.

  • Calibration codes are for diesel injectors (a diesel power-plant is/was available on certain C-Max models, hence the search results). No calibration code entry is required for gasoline injectors when one is replaced.

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