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honda_fox3 07-19-2012 12:25 AM

Codes P0171 and P0174
Codes are P0171 and P0174. They are lean mixtures on bank one and 2. Anyone had these codes before that can point me in a direction? Fuel pump? Pressure regulator?
I dont have a gauge but it seems to have plenty of pressure at the fuel rail. With the motor off key in on position I can hit the relief several times and not get any pressure drop.
I have replaced the TPS and done a seafoam treatment.
Thanks in advance.

Scottina06 07-19-2012 12:42 AM

Re: Codes P0171 and P0174
have you changed the fuel filter? The fuel filter filters the fuel and also acts as the pressure regulator. If you got anything other than oem...that could be the problem. 0171 and 0174 indicate the engine is running so lean that it can't add enough fuel to compensate. So you could also either have an air leak or the o2 sensors think you do.

Frango100 07-19-2012 06:51 AM

Re: Codes P0171 and P0174
If you didnīt change the fuel filter/regulator after your last post of slow starting, i would start with that. If you have a scanner which shows realtime data, you could check the voltage output of the O2 sensors (the upstream ones in this case, or the 1-1 and 2-1) and see if the values change very frequently. If the values are steady, that is normally a sign of bad working O2 sensors. But wouldnīt expect 2 sensors to be bad at the same time. This seems more a fuel supply problem.

honda_fox3 07-19-2012 09:01 AM

Re: Codes P0171 and P0174
I haven't changed the fuel filter. I guess I'll start there. Like Frango100 said I would have a hard time believing that both O2 sensors went bad but stranger things have happened.
Thanks guys!
Any other comments are appreciated.

honda_fox3 07-19-2012 10:15 AM

Re: Codes P0171 and P0174
Well it's at the shop getting a full diagnostic. Couldn't get to it till Tuesday but my brother comes home from his mission today so I probably wouldn't have worked on it till then anyways.

I called the stealership about a fuel filter/regulator of course not in stock and $90 :eek::slapfight::mad:. Hopefully that's not the problem. Could be worse though I guess.

I'll keep ya'll posted when I hear from him. Thanks guys.

Frango100 07-19-2012 06:40 PM

Re: Codes P0171 and P0174
You could go for an aftermarket one for 1/3 of that price. I run an aftermarket and no problems, no idea though which brand it is, probably made in China.........
There is an other thread regarding the change of the filter/pressure regulator and where they had some funny problems with noise after the filter change. Seems due to a certain brand of filter.

honda_fox3 07-24-2012 01:02 PM

Re: Codes P0171 and P0174
just got a call from the shop and it looks like a fuel pump and kinked fuel line are my problem. :mad::( So now who has the best priced pumps? doesn't look too bad. Also which brand?

Frango100 07-24-2012 05:27 PM

Re: Codes P0171 and P0174
My jeep original fuel pump is a Bosch. You can just change the refill and not necessarily the whole fuel pump assy.

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