You explain this nicely, nice job on the video with a total dispense of any b/s. I mean, I'm still kind of lost but I get the gist of it. :)

Great write up bro... I like how well you explained it. May I bring up just a few things I believe would help people? So when you unplugged the MAF with it running and went back to looking at the fuel trims it really didn't show that big of a change. First thing is because if I was you I would have reset the long term fuel trims in the scanner to show the instant changes every time you made a diagnosis change. Second is in order to get into SD mode on GM vehicles you have to set a failed MAF code in the PCM. That is 2 trip logic code so it needs to see the failure 2 times before it sets the code. In other words 2 key cycles unless its changed to a 1 trip failure in the tune. Whenever I tune the VVE table in these I first have to fail the MAF and set the code before the PCM references SD and I can then tune it. Otherwise it still will reference the old fuel trims and then your just tuning in circles. This is probably to much info for the standard person trying to figure out there problem, but I thought it couldn't hurt to add this info for the highly skilled techs. I have also had a lot of these HPFP fail and leak fuel into the crankcase. In fact one was so bad the the engine because to tick from the diluted oil and then would stall from the low rail pressure. Great video and keep up the great work and help you are showing people. Kind Regards, Ryan

Nicely said and done!

Great video. What shuld the LT trims be at at 40-50mph?

Great video. I have sane issue on 5.3l. Could it be just the oil getting sucked in from the pcv? I don't know if it has ther same hpfp like that 6.2l Thanks

Great video on the money bro

I have 2001 gmc sierra with a 5.3l and ive replaced the fuel filter fuel pump and fuel pressure regulator and its still running rich about -31 shft bank1 and 2

I did the same tes but my engine turned off during the procces...is this a normal behavior?

I’m having a 5v reference code also a high pressure voltage high code…. Any idea?

Hello Pete , I have a 2014gmc sierra with 212,000 miles, and I have a P0420 , P0430 and a p2099 code . I've been trying to figure out but it's been beating me. I've replaced all the 02 sensors and nothing changes. I've replaced the cats as well but the codes remain the same. Do you have any suggestions besides getting a new vehicle?

Nice. My 2013 Si;verado had LTFT B1 -25.8%, LTFT B2 -25.8% and P0172 Fuel System Too Rich (Bank 1). Startup takes 15 seconds. Take-off is very sluggish. 140k with O2 sensor errors. P0053 for “Heated O2 Sensor (HO2S) Heater Resistance (Bank 1, Sensor 1).” Fuel Injector leaking.

Good Video i have a 2018 Tahoe with 5.3L only 42,000 KM Check Engine Light just Came on P2099 : Post Cataytic Fuel Trimm Too Rich ? what Gives

What part you change

New Fuel pump fixed it????

I have the same codes and p0430 can runing rish couse that code for the cats

Did you found the problem?

Question- Did you know there is a recall on the High pressure fuel pumps? RECALL - HIGH PRESSURE FUEL PUMP LEAKAGE # 14858: Product Emission - High Pressure Fuel Pump Possible Leak - (Feb 19, 2015) It is ongoing… My 2015 Chevrolet Silverado 1500 with RPO L83 is on it but vin not coming up. Figuring it out with GM now

Ok but mine IS rough running. Very rough running. Replaced fuel pump and re learned the trim several times but it inevitably always comes back in a short time with rich or lean codes and runs rough. What do I do????

I had a throttle body relearn done to fix the constant problem after cleaning it. I think I may have made a mistake I did a fuel composition reset using X431 on my 2011 5.3 flex fuel suburban , currently have e85 in my tank. Now I have 2 code errors p0171-00 and p0174-00 fuel trim lean system lean bank 1 and 2. Did I do something wrong? I would appreciate any help what to do and proceed. Thank you

What about p2099?

I have a Yukon 5.3l with these same codes and I checked the dipstick and had a strong smell of gas from the oil. I just purchased this vehicle a few days ago and Im worried the pumps been leaking for some time and reducing viscosity of the oil. Im going to drain the oil and hope I dont see any metallic shavings. You this failure is common on gm ls engines. Have you seen engine damage from contaminated oil from a leaking fuel pump?

I have both codes on a 12 GMC Sierra. I do have a bad ac condenser though? Like no air cooling at all. Could this be giving me rich codes because of there being a bad ac condenser?

What if the truck doesn’t switch over to closed loop with engine warmed up ?

Nice good info

I need your help man. I got the same codes on mine. 2003 how do I figure it out. Same issues. I have driven it for 6,000 miles with the check engine light coming on and off. Trying to track down what it is and I’ve changed a million things.

I replaced mafs all four exhaust sensors and still the codes come up truck runs good but engine light keeps coming back on

I’ve done this 3 times and the codes keep coming back months later. What do I do now?

Ford Ranger 2014 2.5L 4 cil Gasolina -Codigo del vehiculo: P0172 Por favor ayuda! Ya hicimos varias cosas y mi mecánico no encuentra la falla! Se ha hecho esto: -limpieza de cuerpo de aceleración -cambio de filtro de gasolina -cambio filtro de aire -cambio sensor de oxígeno -se calibraron los inyectores Se le reviso: Válvula PCV Bujías Bobinas Mangueras de aire Presión de gasolina Y el código P0172 sigue apareciendo Aproximadamente 4 horas después de darle uso normal a la camioneta. Que podemos hacer? Mi mecánico ya no sabe que hacer y yo ya estoy cansado. Cada que la llevo me cobra algo nuevo.

Had this issue, garage said alcohol % was showing 47%. They reset and truck back working great But now few months later issue is back. Truck hard to start mornings, rough idle. Reset is only short temp solution. What should garage do? 2011 SLT Sierra 5.3l flex fuel. 185,000km’s

Would installing an oil catch can help this?

My tahoe 2011, I don't know p0175

Awesome video! I need help. I am getting a steady 45 psi on my car 2011 suburban 5.3. I feel like its dumping fuel because my fuel gauge goes down more than normal. I see everyone else mention 50 to 60 at the rails but i am using my expensive x431 scan tool to check everything. All of a sudden after 1 month of using e85 its been extremely bad. Fuel gauge drops fast. I cant find no wet fuel leaks by the engine compartment. My mpg normal at 15 to 18. Now feels like 6. I am also using a scan gauge to read the mpgs and its not bad hwy is 18mpg both dash and scan gaugeii. What the hell is there a small leak some where only when its on? I get no code errors.

Ok. I removed the pcv hose and plugged both ends as per ur video. My trims dropped to normal range! But about a minute later they climbed again. Any suggestions?

Um. I dont understand the end. Is there a part 2 or something??

My 2015 Silverado is throwing the same codes. Also idles really rough at low RPMs. Would that be the same solution?

What code reader is that?

So what part was bad?

My 2016 GMC Sierra have a very strong odor of gas fumes in the cab. My oil smell like gas when I changed it. I Took it to 3 GM dealerships to get it diagnosed no one can find the problem. I have no engine light on either.

Where is part two for this issue?

Is it just as common on the 6.2?

Have a Cadillac SRX 3.0. P0172 and 175.....new high pressure pump installed no fix...

Is this not the ethanol level being detected too high (falsely)?

Ok thank you now what’s the fix

My Longft 1&2 is -25.8

"we're not gonna wait, we're gonna get right into it" then it's over..? Is there a part 2 or what? If so why not post a link to it in your description?

so is the fuel pump the problem?

I only have p0175 and long term is -30%.

Maany b Carnero

And so video cutoff with no solution. Just gave it back to customer and told him to take it elsewhere