p0172 p0175 diagnostics

[rdurham285]

hey guys.

My 03 GT is throwing p0172 and p0175.

Driveability is fine. The only other two symptoms are that my gas mileage is a little low and that on cold start up, the idle is jumpy for 15 seconds or so.

No gas in FPR vacuum line.
I can't see/feel/hear any exhaust leaks

I've got the maf sensor out now and it looks clean, Im going to clean it anyways.

One thing I found was when taking the intake ducting off, there was a paper towel obstructing about 1/8 of the TB screen. But SES remained as well as cold start symptoms.

When checking my FPR, i did faintly smell gas in the vacuum line, however the line is dry at both the FPR and the TB side of the line. And another tick for the FPR, one of my hot starts took a little longer than I thought it should. But turning it off and trying it again, it started immediately. I havnt been paying attention to my cranking times.

I am about to unbolt the fuel rail and see if my injectors are leaking.

Can anybody provide some insight?? specifically on the FPR? is a gas smell in that line after engine operation normal?

Oil smells fine btw.

as far as Vacuum leaks. None that I can see.
Ive checked
FPR, MAP, Brake Booster, and there's one I assume goes to the evap, all in good condition.

-Ryan

[TheOtherNick]

Its leaking a little bit. Change out the FPR.

[rdurham285]

will that cause my jumpy idle by chance?

(thanks for the quick reply)

edit*

my logic says that it's the short term fuel trims doing that? or thats when it's leaking most?

[matt5112]

when the FPR leaks you get un-metered fuel entering the engine, running rich could cause a jumpy idle.

STFT's dont matter too much, if you have the ability to, check the LTFT at idle. It should be pretty close to zero.

[rdurham285]

welp,

I changed the FPR and initial startup is much better without any surging or idle searching.

I will find if the problem persists after two more "Drive Cycles"

-Ryan