Guys I have been getting a random p0172 code (too rich) during boost with the GM re-flash. Last time it happened freeze frame said I was at 8psi manifold pressure. I think the long term fuel trim was like -9 and the short term was -15 (I may be getting those switched around). Is this normal behavior for the re-flash? I am running cobalt ss s/c injectors, m62 with stock pulley, and no H/E. It seems to have started since it has been getting warmer out. Maybe a H/E is in order? A couple weeks ago I stalled my car while starting it and it ran really shakey and threw a injector circuit code on bank 3 (injector stuck open?). It fixed itself out but I wonder if that injector is faulty?

the reflash adds more fuel the higher in the rpm. so the bigger injectors may be the issue?

just an idea, i had a to rich condition and put the stockers back in and it felt alot bigger, or i just turned the fuel pressure down.

I thought the reflash was designed for cobalt ss s/c injectors or the ones that came with the kit? Stock injectors are maxed out on the stock engine aren't they?

It depends on the kit. I think the later GMPP kits had larger injectors and the earlier one were a few pounds less. I don't remember the exact numbers though. Are you using the injectors that came with the kit? What elevation are you at?


-I drive my car to work-

I just had that exact problem. I am running the injectors with the kit. When i tried to swap to the 02 rail with gmpp stage 2 42# injectors i was throwing that code under wot and my car would bog down after about 3 seconds. I swapped back and everything was fine. I am assuming my injectors were too big without a proper tune. You should not have that problem tho with stock cobalt ss/sc injectors.


black 03 z24 with a few mods

Yeah im thinking the injector in cylinder 3 may be randomly sticking. It goes months sometimes without doing it. The injectors were used when i got them.

Yea id deffinatly try swapping injectors


black 03 z24 with a few mods

yeah you need a good tune with bigger injectors, period.
mine wouldnt barely run at all on stage2's, id go through a half a tank of fuel it was so rich, in 30miles. Not even joking!

mine with lots of tuning from Vince finally runs okay...still starting issues every now and then and at WOT im fully rich (10.0), but at least normal driving is good and even regular acceleration. the GMreflash is for 36lb injectors, stage 1..as you thought.


04 Cav. 2dr. 5spd. My DD. 'Nuff said.

Its happening more often now. I have ran some fuel system cleaner through the tank.
Here is the freeze frame from the last time.

Engine Load = 85.49 %
Engine Coolant Temperature = 88 °C
Fuel Trim Bank 1 Short Term = -9.375 %
Fuel Trim Bank 1 Long Term = -14.062 %
Intake Manifold Pressure = 12.038 psi
Engine RPM = 1,493 rpm
Speed (OBD) = 32 km/h
Timing Advance = 8.5 °
Intake Air Temperature = 64 °C
Throttle Position(Manifold) = 19.216 %

I have no other codes besides p0172. Could this be a bad o2 sensor?

Well I was going to get my injectors prof serviced, but I found them on amazon new for $33, which is a steal if you ask me (http://www.amazon.com/gp/product/B000EQVS4W/ref=oh_details_o01_s00_i00). Got 4 of them coming and a new ac delco o2 sensor for good measure (mine has 110k on it probably time to replace anyways). Should I get the one after the cat as well?

Finally replaced the injectors today with brand new ones from ac delco (only cost me $130). So far so good. My fuel trims are WAAAAAAAAAAAAAAY better long term is mostly 0 where it was -12-17 before and short term only spikes up to -10 every once in a while. I assume this is normal? Fuel pressure with key on is 57, idle is 50 and with no vacuum to the reg its 57-60. So my regulator seems to be doing it's job.

Mr Newb wrote:Finally replaced the injectors today with brand new ones from ac delco (only cost me $130). So far so good. My fuel trims are WAAAAAAAAAAAAAAY better long term is mostly 0 where it was -12-17 before and short term only spikes up to -10 every once in a while. I assume this is normal? Fuel pressure with key on is 57, idle is 50 and with no vacuum to the reg its 57-60. So my regulator seems to be doing it's job.

sounds like you are good to go!

Moral of the story save yourself headaches don't buy used injectors