So I am still getting this p0172 code and it is driving me insane.
-It seems like it only happens when I am above 3/4 a tank of gas. After three ignition cycles it goes away and doesn't come back on until I fill back up. I do seem to run rich still after just not enough to trigger the code.
-My long term fuel trim is almost always around -14 to -16. Short term seems to hover around 7 to -7 most of the time. (I usually hit -15 during decel for a split second and then it goes to 0. (That's also when it throws the rich code usually) During heavy throttle both fuel trims go to 0.
-I had my fuel filter changed a while back and was told it was pretty dirty. Could my gas tank be clogging my new injectors again?
-I was throwing the code all the time before I replaced my used ss s/c injectors with brand new ss s/c injectors. I am running bp 93 octane gas.
-FPR doesn't leak fuel when I pull the line. Fuel pressure tested out OK back when I checked it after I replaced the injectors (I might test it again this weekend).
-Fuel pump? A couple weeks ago my car did a weird stumble during boost (felt like it tried to die) on the highway a couple times hasn't done it since...
-Could be the EVAP? (maybe why it throws the code when the tank is fuller?)
-Plugs looks perfect no fouling.
-Map reads slightly less vacuum than my boost gauge so I'm pretty sure its ok.
-Throttle position sensor looks OK (although it doesn't read 0 at idle its like 8% which I have been told is just how the re-flash works)
-I can hear/feel a very slight shake at idle every couple seconds or so (it's always done that even before the S/C)
-Also in 1st, 2nd, and 3rd (slightly) while in traffic my car likes to jolt a lot during decel. I have read this is normal for a stick. So I'm not convinced this is an issue or symptom.
You said you use bp gas? They were just in the news out here in the midwest for knowingly releasing bad gas for sale that's causing some people issues. Aside from this idk what to tell you, I hated the reflash when I had it. I never really got a rich code though.
I have been using Quick Trip the last 2 fill ups and no stuble.... Maybe the bp gas caused the stumbling. I want to get a real tune, but I want my car to run normal on the re-flash ideally before I switch. Not sure it would be good to have a random issue like this with a tune. I am getting close to have a mechanic look at it, but most look at you and say its not stock I can't help yah leaving GM as the only option...
I was having issues like yours, car running rich and bucking during decel and things like that. So as stupid as this may sound,
CHECK ALL YOUR GROUNDS. On Tuesday, my car decided to not start. looked around saw nothing abnormal at first. Wiggled the battery cables, and the end of the ground cable not attached to the battery was loose on the trans. Tightened that sucker up, and car has been back to normal ever since.
Where are all the grounds on this car?
I had the same issue after I bought my current cavy. it would run like crap and die randomly. I checked the ground strap on the trans. and voila. tightened it up. car has ran fine for 100k since.
Tyranny ground was tight as can be
Tranny not tyranny haha stupid auto-correct.
I'm def leaning towards electrical. I guess I'm going to check the wires going to the injectors and see if.one is shorting cuasing it to stick open randomly. Any pointers for this?
Short term Fuel trims were almost perfect today no change... this is really hard to troubleshoot! What does everyone else's fuel trims look like on the crap flash?
