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Dan, Technician
Category: Ford
Satisfied Customers: 26226
Experience:  Independent Shop Experience, 2 Year Automotive Diploma, & Access to Information Database
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2003 ford f150 5.4 cant get rid of po175 code changed

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2003 ford f150 5.4 cant get rid of po175 code changed thermostat spark plugs and temp sensor cylinder head lftrim 1 28 lftrim 2 -16 got better once i changed thermostat was 26 before that miss fires on 5 6 7 8 none on bank 1 what am i missing
JA: Have you checked the connectors on the sensor itself? It's important that they not be loose or corroded.
Customer: yes
JA: Are you fixing your F150 yourself? What have you tried so far?
Customer: yes
JA: Anything else you want the mechanic to know before I connect you?
Customer: no

Hello, my name is ***** ***** I'm here to help get your problem solved.

Is it still misfiring on bank 2?

Customer: replied 8 months ago.
not enough to set code but on my scaner i can see all the cylinders on bank to miss a clear up

Some possible problems are front bank 2 oxygen sensor, purge solenoid, mass airflow sensor, or timing chain. Start with the easiest and work your way to hardest. You can Disconnect purge solenoid and block off lines to see if that helps if so replace. If not then you can unplug front oxygen sensors to see if that helps if so replace if not unplug mass airflow sensor to see if that helps if not replace. If there is still a problem then I'd suspect timing chain. When this engine is properly in time, the crankshaft keyway will be located at the 11:00 position which is TDC, the driver's side camshaft sprocket mark will be just slightly on the 1:00 side of 12:00 and the passenger side sprocket mark will be at the 11:00 position. My goal is to provide 5 star service so please let me know if you have any questions, thanks.

Customer: replied 8 months ago.
ok ill try that and let you know

Sounds good, you can reply at any time without additional fees so make sure to let me know if you need anything. Thanks.

Customer: replied 8 months ago.
tryed everything nothing changed truck runs really good just runs a little rough at idle and only code is po175

You checked timing?

Customer: replied 8 months ago.
have to remove the valve covers to do that

I think that is next best step, only other thing I can think of is leaking injector.

Customer: replied 8 months ago.
i was leaning towards that how can i check that

Here is also information from manual related to code, let me know if you have questions. Thanks.


You will want to pull injector rail and check spray pattern. You can also disconnect each injector/coil one at a time, each one should drop rpm the same amount if not that would indicate a problem with that specific cylinder.

Customer: replied 8 months ago.
ok ill try that

Sounds good, if you aren't able to find problem with injector then you will need to check timing even though it is a pain. Let me know how it goes or if you run into more questions. Thanks again and please do not forget to rate answer.

Customer: replied 8 months ago.

Thanks, I'll be here if you need me.

Dan and 4 other Ford Specialists are ready to help you
Customer: replied 8 months ago.
did a cylinder balance check unpluged num 5 cylinder injector 6 7 8 cylinders went to 0 pluged it back up all cylinder went from 0 to -17

So it sounds like problem is on cylinder 5 which would either be valve or injector.

Customer: replied 8 months ago.
ok ill try changing the injector because off idle all cylinder balance at 0

I​ have a feeling its going to be a valve problem, keep me updated. A cylinder leakdown test might not be a bad idea. Thanks.

Customer: replied 8 months ago.
ok thanks

N​o problem, let me know how it goes. Thanks.