2002 f-150 5.4. Truck is running and idling rough. Keep getting the
p0172 engine code. Cleaned the filter and changed the mass air sensor and now it is worse. Please help

 

That's rich bank 1 - passenger side. You may have a leaky fuel injector on that side.

 

Ok now i am getting p0172 and p0175 which means bank 1 and bank 2 are running rich. Changed mass air flow still getting the same codes any ideas?

 

Deleted: User has two threads.

 

User has two threads going about the same thing. So check this one first before you reply -

https://www.f150online.com/forums/19...-bank-one.html


lhicks503 - Don't do this.

 

J brew i just bought the truck last week. The previous owner said he had to replace one of the fuel lines a week before because it busted. One from ford was 300.00 so he had a local hydrolics shop make one for him. He said the check engine light had not been on be fore. Could this have something to do with it.

 

Sorry about the double post wasnt sure which one to post it in. Want happen again.

 

Alright, you need to check your pressure regulator. If your regulators out and over-pressurizing the rail, residuals end up in the combustion chamber (so to speak lol) , hence rich DTC's.

So Fuel pressure/reg test would be in order.

You have problems on both banks, so something is going on. Maybe with LTFT's LongTermFuelTrims. It's my bet that the regulator is out.

 

And on my truck that is mounted on the fuel rail? If that is the problem i will have to replace the whole rail correct.

 

Nope, just the reg. It's easy. On the drivers side of the rail/ two allen head bolts.

 

J brew i just bought the truck last week. The previous owner said he had to replace one of the fuel lines a week before because it busted. One from ford was 300.00 so he had a local shop make one for him. He said the check engine light had not been on before. Could this have something to do with it.

 

I doubt it, unless they screwed with the rail. I doubt it. Fuel is controlled at the rail.

 

Alright jbrew i replaced the fuel regulator and got the p0172 and p0175 codes again.

 

You didn't ask what to do, just what things where and location. I wouldn't throw parts at it like that, - it can get expensive. This site can save you a few bucks, but were not mind readers...-Uknow.

You should have invested in a pressure tester. The cheap ones are around $30. You need to check pressure at the rail. Fuel and Regulator pressure to confirm their within spec. Sort of a bi-law, -always~ fuel system first/supply/pressure to the injectors.

Then, pull the rail loose (4, 8mm bolts/lift off the injectors/pull the injectors/insert in the rail/reconnect battery/turn key to run(not start)/check injectors for leakage.

Lay a few rags down to protect the coils and to keep fuel away from the plug chambers. Because no matter how careful you are, there will be residual fuel dumped here and there during procedure. Keep it clean and the rest is common sense.

If injectors leak with key on/ their bad.

Your PCM is telling you your rich. Trust that for now.

 

Thanks alot for your help jbrew. I will try that saturday morning and let you know what i find out.