FocusCanada Forums

Common problem.... yes, i've searched around, but my symptoms seem to be a wee bit different...

I get the somewhat typical stumble/feels like a misfire after each shift... usually in the low 2k's of the powerband. Started out of nowhere during a recent road trip.

The thing is, its intermittent. I can drive the car for sometimes a half hour before it starts, sometimes only 15 minutes. Only happens when the engine is warm. Once I turn it off and the engine is cool again, everything goes back to normal. The (somewhat useless) temp gauge shows nothing, and I did a full coolant flush about a month ago. I've also:

- Tried both DPFE workarounds. Also tried to just block off the EGR altogether, and tried unplugging the DPFE itself. No change.

- Replaced the gasket on my IAC, as my brother didn't do it right after my manifold swap a couple of months ago. Also tried replacing it with a spare I have.

- Double checked for any vacuum leaks, but I can't find anything.

- Plug wires are all on tight. Haven't pulled any plugs yet, but i'm thinking its something electrical due to it just starting in at random

- Cleaned MAF

- TPS was replaced just over a month ago

- About to change the fuel filter (needs to be done anyways)

And yes, I DID re-set the ECU (unplug batter for a half hour) after trying each thing above. Still no luck.

At this point, i'm running out of thoughts. Only things I can think of are that the coil is on its way out, but not there yet, or might be an O2 problem. I'm not getting a CEL or any codes (have a code reader), which makes it that much more confusing.

Anything else I should be checking for? All of my mods are in my signature....

my car is almost doing the same thing, but it wants to stumble when I hit the gas more, like all the way down, I think it's the fuel filter, I'd say change it and see if it resolves the problem.

We had the same issue last year and never threw a code and was hard to track down.

It was for us anyway, the stupid DPFE.

Stumbling when the car got hot and even would stall at stop lights occasionally.

Now it's all good.

check for that harness that goes on the coil.....i recenly had somethin like that....at least it kinda sounds something like that...just check it anyway bro
good luck

upstream o2 sensor.
I had this on my focus and had no codes or anythign come up.

- Fuel filter changes, no different
- Checked coil pack wires, all look good.
- Tested the living hell outta the DPFE, nothing i've done made a difference. Will be getting a chip soon to disable the EGR system anyways.

Mine was doing that. DPEF workaround works out great and replacement of DPFE does the job.

Its actually called a PFE sensor, if you read the workorders i guarentee you it will say PFE. I dont know why people still call it a DPFE

Older Ford manuals refer to it as the DPFE. The Delta is somewhat redundant, as if i'm not mistaken, its really the only kind of PFE out there.

Hmm... still no CEL, but I scanned it for s***s n' giggles, and it appears I have a P0300 pending. Random misfire (duh!).

According to the code, it says that either the EGR is stuck open, or closed (Had this problem when my EGR system was stock, i've since used a DPFE workaround, and blocked off my EGR, and it hasn't changed).

P0300 - Random Misfire
The random misfire DTC indicates multiple cylinders are misfiring or the PCM cannot identify which cylinder is misfiring. Camshaft position sensor (CMP)
Low fuel: less than 1/8 tank
Stuck open EGR valve
Blocked EGR passages
One or more EGR passages may be blocked or partially blocked. If this is the case the Misfire Detection Monitor will indicate the EGR port to check for possible blockage.