Code 44 only during long climbs to mountains

[dynoH350]

Purchased 1994 Blazer K1500 last year. Alot of work done to it since, no mods, all stock. 222k miles
My main issue now which has been persistent since purchase is I get a code 44 Lean Condition only during long climbs up to mountains. The light turns on then turns off after I am back on level roads. Recently on the last climb the check engine light is coming on earlier in climb and stays on longer. The last climb I did while the check engine light was on and sitting it traffic it started getting a rough galloping idle until I revved the engine up over 1k RPM. Check engine light and galloping went away approx 5 minutes after level roads. Additionally there has been a persistent rough idle that feels like a slight miss, you can feel a slight rumble every couple seconds just during idle.

Applicable work since purchase:
Ignition: New Cap, coil, plug wires and spark plugs (When I first pulled the plugs cylinder #6 had heavy white ash buildup. Just pulled #6 again after 2k miles and had some ash build up and pink in color see photo attached)
Alternator tested and is ok, new battery
New drivers side exhaust manifold and collector gasket (exhaust leaks gone)
Checked for vacuum leaks with brake clean around intake and TBI no noticeable change in idle
New fuel filter, checked fuel pressure - holds at 12psi at idle and revving in neutral
Injectors appear to be spraying evenly and nice cone shape.
New PCV
New CTS, leads were corroded, rewired new leads

After driving the last long climb with check engine light did the following the next day (this weekend):
New MAP sensor and EGR, Just drove around the neighborhood and no noticeable changes. Also no surprises when replacing, EGR appeared functional and MAP looked good enough was GM.

I plan to replace O2 sensor and do a compression test as well.

You must be registered for see images attach

 

[tayto]

heavy white ash check your base timing is correct and correct spark plugs are used. your fuel pressure is good but i suspect injectors probably need to be professionally clean or replaced. i like cleaning oem injectors but others have had success with new aftermarket. just don't expect the same longevity/performance from the as they will be offshore.

 

[docstoy]

So you still have rough idle ? And you changed egr valve ?

 

[dynoH350]

heavy white ash check your base timing is correct and correct spark plugs are used. your fuel pressure is good but i suspect injectors probably need to be professionally clean or replaced. i like cleaning oem injectors but others have had success with new aftermarket. just don't expect the same longevity/performance from the as they will be offshore.

Thank you for the insight. The plugs I installed are Autolite from O'Reillys that they had said are correct for the vehicle, I dont know exact model, but I got the cheaper ones and I am afraid that they are the double platinum ones, heard those foul quicker in older cars. Will switch out plugs, any recommendations on plug brand and type? I will check timing is 0deg and look into cleaning my injectors. Will also do a bottle of SeaFoam on an empty tank.
EDIT: They are Autolite Copper Core plugs, nickel copper, gap online says 0.044

 

[dynoH350]

So you still have rough idle ? And you changed egr valve ?

The persistent rough idle that feels like a quick miss is still there after the EGR valve was replaced. The rough galloping idle was only once at elevation with check engine light on sitting in traffic. After driving a bit on level road the gallop at idle did not return. I have not done a long climb to mountains since new EGR and MAP

 

[docstoy]

If no other plugs look similar to #6 then possibly some top engine cleaner to clean valves but if your not close to oil change time would wait to do that right before you change oil and let engine get to operating temp. before changing oil . Don't know how yall feel about top engine cleaner. Just my 2 cents.

 

[dynoH350]

If no other plugs look similar to #6 then possibly some top engine cleaner to clean valves but if your not close to oil change time would wait to do that right before you change oil and let engine get to operating temp. before changing oil . Don't know how yall feel about top engine cleaner. Just my 2 cents.

#6 was by far the worst, see attached picture of the old plugs when I first replaced them.

 

[docstoy]

Not wanting to jump to conclusions but have you ck'd compression on all cylinders ? If that is good then you could possibly have a worn valve guide and or leaking valve seal(s) . Have you had valve covers off and it looked normal ?

 

[dynoH350]

Not wanting to jump to conclusions but have you ck'd compression on all cylinders ? If that is good then you could possibly have a worn valve guide and or leaking valve seal(s) . Have you had valve covers off and it looked normal ?

Have not done a compression test, will make that a priority.
Have not had valve covers off to inspect.
Would that also cause the Code 44?

 

[docstoy]

The reason for compression ck is obvious, carbon on that plug, if it's good have seen trucks that had carbon accumulation on top side of heads around valves, that being from running engine at higher than normal temp. or maintenance or oil type . If around valves then oil can accumulate an leak past seals. Wish you the best of luck.