67firebird455

My 2021 has this same issue. Seems to be the driver's rear door. Drives me absolutely nuts.

Hey all, me again. We finally got it all put back together and seems to be running great (except the occasional P0430). It's on the passenger side, the one that had the bad injector on one cylinder, then turned around and had a bad lifter on #4 on the same side. It wouldn't surprise me (with my luck) that all of that damaged that converter on that side. My friend and I datalogged for 1/3 of a tank of gas today after hammering on it pretty good a few times on the freeway, and no check engine light for low catalyst efficiency yet *knock on wood*.

Well boys and girl, I might as well have just pulled the damn motor out... It's literally stripped completely besides crank, rods, and pistons. Being that it's 4WD, we had to remove the rack and differential. I ordered a complete DoD delete kit with a new timing chain, all gaskets and bolts from Texas Speed & Performance on 1/24 in the evening. I was told on the 30th that it was being packaged and shipped that day. Nope. I have a new oil pump, pickup tube, O rings, gaskets/seals/RTV, water pump, radiator hoses, and the heads rebuilt with new valves and BTR springs, but can't get TSP to ship the freaking order in a timely fashion, and am now hung up waiting with the pan off this L86.

We’re looking to pull the heads this week, and have both rebuilt. TSP L86 non DoD cam is all I can find that eliminated DoD, but retains VVT without a cam phaser limiter which requires even more tuning (good ol California, checking Cal IDs and CVNs now). $1200ish for DoD elimination kit with cam, plus whatever the heads cost to rebuild. I already had to repaint the roof and hood because of trash clear coat, now it’ll be time to repaint the whole car because the doors and fenders up near the top are worn down to bare paint and are dull. This car man…

Update here. After replacing all injectors, both fuel lines, purge valve, gaskets... It ran great, for a day or two, then misfiring now on #4. Compression test on cylinders 2 and 6 showed 230 and 250psi, cylinder 1 showed 240, but poor old #4 showed 150psi. A leakdown test we ran tonight shows it's leaking through the valves on #4, so I've got my work cut out for me, and wife is pissed and looking at other cars. Thoughts or recommendations from those who have gone with a non-AFM VVT cam/lifter swap?

I actually had a 99 turbocharged 6.0 TA. It’s not exactly comfortable in the back seat, but boy are they fun, and they get crazy good fuel mileage!

Super nice truck man. We get a new car every 10-15 years and try and pay cash. I despise having a car payment. Wish I would’ve scored the 02 WS6 I had my eye on for my almost 16 year old son… I would’ve had a backup car (despite seating four) and not having to borrow mom’s 05 green convertible 6 banger mustang. Haha For now, to get the entire family around, we’re using my ‘21 Duramax, but 3 wide in the back seat and two teenage boys gets a bit old.

Same here. I’ve had it for 24 years now. It was an old 6 cylinder sprint with a Saginaw 3 speed. The only upgraded option was deluxe interior. I got it from a friend, and it had a ‘75 Pontiac 350, with ‘76 455 heads (suuuuppperrrrr low compression) and an open 2.78 rear end. Turbo LS now, TH400, 9” rear. I love that car, but stupid expensive to work on. It needs a lot of love in the body department, but still a lot of fun to drive when I get the chance!

@Karnut - I hear you. Was my first thought too, and still haven't entirely ruled it out. The P2150 and P0302 are gone now with the injector replacement, but the fuel ration imbalance between cylinders and the odd pressure/injector balance rates lead me to believe these are junk ass injectors even though they look legit. The eBay seller didn't even give any pushback when I asked if they were genuine GM injectors, they just immediately offered a replacement or refund. We'll find out when I get the set of 8 fresh ones from rockauto on Tuesday! @Stonewood - That's the story of my life brother! I figure putting a bit of money in this pig beats a car payment! It's been paid off for 6 years now, and it's been a pretty solid family wagon. Borrowing my mom's mustang has reminded us how lucky we are to have this huge SUV! Will update when we get a little further next week!

HAHAHA that's what I'm saying. Reset fuel trims, still get random P219A and/or P219B. Injector balancing is off, so I can nearly guarantee you these are fake GM injectors (they look and feel legit). Ordered rail removal tools, and 8 genuine GM injectors from rockauto along with another set of replacement fuel lines. We'll give it another go next week I guess.

Got a new purge valve (it came with a bolt), inspected the end of the hose, and reset codes. Now after two drive cycles I've got P219B. I may need to bust out HP Tuners and reset fuel trims after all the nonsense.

https://photos.app.goo.gl/JzSSGkQApDTGk6FW9 That purge valve seems awwwwfulllll loose. Everything upstream looks good except that. I've got a sneaky suspicion the wrong bolt is in that valve. Going to replace it and give it a shot.

Well, we got the injectors swapped with new rails, high pressure lines, both injection harnesses, and intake gaskets... No more misfires, but, the dreaded P219A and P219B now. Seems to drive fine, but after a couple of drive cycles, both DTCs pop up.

Tonight, we removed the intake, fuel lines, one rail and set of injectors. I ordered new OEM injectors, fuel rails, high pressure fuel line, and injector harnesses since I'd rather not open this thing up again if I can avoid it. Since this is a 2015, there are no small boots and the end of the damn injectors were nearly seized to the head, so I ordered two seal kits from GM also. PB blaster certainly helps to loosen things up, but this job is miserable, especially when it's the wife's car.

Thanks @steelerdude15 and @rav3 for taking the time to respond. I drove it over to a friend's to hook up to his scanner, and although the check engine light was on, it was fine until it got to temp, then a dead hole, flashing check engine light, and traction control light. Cylinder 2 misfires were incrementing, so sounds electrical. Going to pull the intake and try and locate some injectors tomorrow, inspecting the injector harnesses while it's apart, and cleaning the intake while it's off. I reminded the wife we should've pulled the trigger on that 02 SS camaro I found for my soon-to-be-licensed son. We could've had a backup car other than my 67 in this rain! Thanks again guys.

Wife drove across town (in the rain) in our 2015 Yukon XL Denali and after getting gas, made it about 1/4 mile, stopped at a light, then began to feel a vibration, and check engine light started flashing. She made it home, I scanned it and came up with the above codes. I fired it up, cleared the codes, then the miss started again. We've got just under 120k on this thing. Are we thinking injector #2? Appreciate any insight!

@jimbigg - You have to flip the small flap on top of the cable up. Just be careful not to break it off, once flipped directly up away from the board, the ribbon easily slides out. @Nicholas Trifiletti - Thanks a lot man. Appreciate the thanks. I'm so glad it's saving other people time and money. If my front screen dies (still on stock flipped cable), I'll take a video how to and post it on youtube, then share here to answer any possible questions others might have.

Just disassembled my third row screen again today after receiving my replacement ribbon cables. R&R'd in under 10 minutes and am back up and running! I should go back through my original post and circle the screw locations requiring removal. To split the screen cover, I used my pocket knife to separate, keeping pressure pulling apart and working my blade around the perimeter.

I attempted this repair again, but on the third row screen in our '15 Yukon XL Denali... nada. Was forced was to order the 20pc replacement pack on Amazon and praying it works. GM REALLY needs some serious QC changes.

My 2015 Yukon XL Denali is the same way. The attached image is after paying for a deep cut and buff. Couldn't cut any further without burning/destroying what was left of the pathetic clear coat. The entire roof of the car is this way also and will need to be repainted. The rest of the car looks okay except a couple trim pieces near the rear windows...

Fantastic! Glad the post helped you out!

Fantastic. Thanks a lot Mark! Glad you got it all sorted out buddy! Now... if I could get someone to assist me in eliminating the magneride on my '15 Denali, I'd be grateful! ;)

Has anyone been able to successfully install a standard shock on these things with a resistor kit? I'm dreading replacing all four of mine, but I cannot tolerate riding around town, feeling like a low rider with rigid suspension.

Thanks Mark. I'm sure you saw the link I posted was reverse, that is the first thing I did notice. At least it's definitive now so others can save some serious cash!

I did, but no specifics on width/pitch/length or anything. I should have measured and really taken a look at mine when I had it apart but was in a dang hurry because we were leaving on a 6-hour trip up to the time share and didn't want all three kids in the third row fighting. hahaha I have a feeling this would work https://www.ebay.com/itm/Flat-Ribbon-cable-40-Pin-0-5mm-Pitch-200mm-long-FFC-FPC-Reverse-Direct-1pc/112412362149?hash=item1a2c4c85a5:g:EMUAAOSw-K9ZHqwL