[rayhawk]

I have a 2016 SS. I'm returning my car back to stock, and I got a P050D rough cold start CEL now. I had an LT2 intake manifold, and the car was tuned for E85, and I had a ported throttle body, no other mods.

I removed the LT2 manifold, and put the stock one back on, and reloaded the stock tune. I also put the stock throttle body back on. Car drives fine, but I got the P050D code. I figured I had damaged a gasket on install, so I took the stock manifold back off, and reinstalled with some new gaskets. I got the same error code again.

I understand this can be due to injector issues or a manifold that's not seated correctly. It seems pretty unlikely that an injector just so happened to have a problem, since I didn't mess with anything but the intake manifold. What's the easiest way to narrow down the cause of the code? I did leave the E85 sensor on the engine since I couldn't get the fuel line removal tool into it, but I don't see why that would cause any issues.

[Ventmaster]

these two sites claim to have the fix:
https://obd2pros.com/dtc-codes/p050d/
https://carscounsel.com/p050d-code/

I'd just be sure you don't over tighten the manifold mounting bolts- the gaskets there deform very easily and create a leak if over tightened. You need to tighten in an alternating pattern and they max out at 89inch/pounds. MSD recommends doing this in at least 3 passes sequentially tightening until they're 89. They also recommend blue loctite on those bolts.

[rayhawk]

Some more digging seems like the injectors are usually the issue here. So I did some data logging and found the following number of misfires during a cold start:

Cyl 1: 2
Cyl 2: 0
Cyl 3: 22
Cyl 4: 270
Cyl 5: 1
Cyl 6: 26
Cyl 7: 2
Cyl 8: 1

So I guess I'll replace the #4 injector, should I just plan on replacing #3 and #6 too? I'm guessing the cylinders with just 1&2 misfires aren't worth worrying about.

[KingLT1]

I would replace the whole set.

[GreyGhost702]

Alternatively, depending if budget is an issue, if you have the tools just remove the injectors and clean them up. You'll want to do new seals as well. If they've been fouled, sometimes just cleaning the tips can do the trick. Though replacing the internal screens and having them serviced isn't a terrible idea either depending on the milage. Of course, if none of that sounds appetizing, ~$450 for a set of injectors and just cry once. Assuming it's the fix. Sometimes it's better than battling injector seals. Though if I had to do it again it wouldn't be so bad.

[rayhawk]

Appreciate the feedback. I'm selling the car, so I'm just trying to fix what is broken if possible, but I understand the seals can be a pain. The car only has 47k miles, so I'm thinking they are just a bit fouled, especially since I don't get any misfires after the cold start. I haven't been driving the car a lot the past 2 years or so. Is there any chance some injector cleaner would be enough to clear up the issue?

[GreyGhost702]

Originally Posted by rayhawk

Appreciate the feedback. I'm selling the car, so I'm just trying to fix what is broken if possible, but I understand the seals can be a pain. The car only has 47k miles, so I'm thinking they are just a bit fouled, especially since I don't get any misfires after the cold start. I haven't been driving the car a lot the past 2 years or so. Is there any chance some injector cleaner would be enough to clear up the issue?

Not sure how effective injector cleaner is on DI injectors. You could give it a shot but you'll need to put the fuel and treatment through the system enough to work it, which means putting the miles on.

[bishopts]

i see that code a lot after ive depressurized the high pressure fuel system. i usually just let it idle for a little bit. then go back and clear the code and it doesnt come back. its mostly caused by low and unbalanced fuel pressure in the rail.

[rayhawk]

Update, code is gone now. I ran a bottle of BG 44K injector cleaner through it, and just drove it around for a week. Could be a coincidence, but either way the problem is resolved now.