2003 Thunderbird engine miss. Not cop problem (just changed them)

[John Hayman]

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If it were me, I would call the dealership and ask for the actual mechanic that looked at your Tbird to call you back. Ask for specifics in layman terms what was meant by Drop. The only time I have used or heard the term "Drop" when it comes to cylinders is when I was running the quarter mile and lost due to a loss of power because I "dropped" a cylinder. The other term with engines with "drop" is a compression test IE losing compression due to bad rings or a burnt piston, but that has nothing to do with COPS.

If anybody owns a 1996 or newer vehicle should own an OBD II handheld or a wifi/bluetooth dongle. The OBD II can save you multitude of dollars over what the unit costs in self diagnostics.

In this case, would the dongle thingee you mention tell me what is the problem? Don't dealers have these dongles?

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[Transporter]

In this case, would the dongle thingee you mention tell me what is the problem? Don't dealers have these dongles?

The Dongle is an OBD II interface device that talks to a laptop, smart phone, or tablet via WiFi or Bluetooth depending on the model and what the user needs. It can make it cheaper to get one as the smart phone takes the place of the processor in an OBD II handheld plus the Dongle can be left installed all the time and the programs on the Laptop/iPhone/Android/Tablet can read and show all kinds of engine and electronics date live.

I am sure the Dealer used there full blown diagnostic interface to look for the problem. What I am saying is that a Dongle or an OBD II handheld is a great investment for anybody that own a 1996 or newer vehicle. In other words buying one will pay for itself the first time the check engine light comes on and you read the code and it is something simple instead of going to the dealer and paying $125 for a diagnostic fee! Plus if you try what I suggested to get the Tbird to throw code(s), you would be able to read the code immediately.

https://www.harborfreight.com/zr4-obd2-code-reader-63808.html

https://www.amazon.com/dp/B075FQH8JR/?tag=thunderbirdforum-20

https://www.amazon.com/dp/B01BY2CK32/?tag=thunderbirdforum-20

The only issue with the Dongles is to make sure they will interface with your phone or tablet plus that they don't need an expensive APP/Program downloaded to use them. I have a $14 dongle that I keep plugged into our Tbird that talks to our Kindle Fire and shows RPM, Engine Temp, cylinder head temp, throttle position, estimated horsepower, and on and on all in real time.
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[Lucy]

So did you find the problem?

 

[edward301]

After reading all these posts, one thought came to mind. Have you checked your EGR valve,
it can cause some issues similar to the one you are experiencing.

 

[BluByeU]

I would like to suggest the plug/ jack connection for the Mass Air Sensor. It must be disconnected to remove the cold air intake to get out of the way to work on the radiator, upper hoses & thermostat.


It is possible that this connector is not pushed together properly or a pin is damaged when the cold air duct work was re- installed.

Another thought in the same area is the air filter box may not be properly latched.

Another place to look is at all steps taken to replace the cops. Stuff that was disconnected or moved to gain access to the cops may not have been put back in place correctly.
Just some thoughts.

 

[DennisC]

Hi John, Did you ever solve this problem? I have the exact same issue with my 2005. 23,000 miles. gave me a P358 code (failed coil on #8). I went to Ford and paid $80 for one coil. Still does the same thing. Put a noid light on the injector wire and it shows that the computer is sending pulses to the injector so no fuel issue there.. If I use manual on the trans and shift it the miss isn't noticeable until 5th gear. At like 35-40 mph and above. Any extra throttle shakes and misses... very annoying.If I downshift it and punch the throttle, it is not noticeable. I replaced the computer two years ago and am wondering if the computer is the issue. Thanks, Dennis

 

[biddle]

Hi John, Did you ever solve this problem? I have the exact same issue with my 2005. 23,000 miles. gave me a P358 code (failed coil on #8). I went to Ford and paid $80 for one coil. Still does the same thing. Put a noid light on the injector wire and it shows that the computer is sending pulses to the injector so no fuel issue there.. If I use manual on the trans and shift it the miss isn't noticeable until 5th gear. At like 35-40 mph and above. Any extra throttle shakes and misses... very annoying.If I downshift it and punch the throttle, it is not noticeable. I replaced the computer two years ago and am wondering if the computer is the issue. Thanks, Dennis

If you look, @John Hayman has not been on the forum since 2019 and sold his car- https://forums.fordthunderbirdforum.com/search/18691/