Injector bores different sizes?

2005, 210k. Bores 1 and 4 are larger than 2 and 3.

I replaced the injectors and a bunch of other stuff and have been struggling to find an air leak. I think it's at the injectors as the seals for 1 and 4 freely move about, a mm or 2.

Swapping no difference, 2 other sets of OEM seals no difference.

I threw out the old densos and the orange seals they had.
The new densos came with black seals. The two other sets of OEM seals and they are also black and exactly the same size as the other new ones. What gives??




I coated them in bearing grease to see if that was the cause of the air leak (or other options being O2, air-fuel sensors, exhaust manifold gasket, valve gasket, PCV valve, plugs, poorly mounted: throttle body after cleaning, or maf sensor after cleaning, or air box mounted poorly) and it ran OK but slightly rough, and threw no codes, yesterday.

Today it's back to the 3190 code (it spent awhile at 2195).

I ran smoke check and can't find any leaks since I cracked the valve cover with a crescent wrench, on the pcv valve.


Any idea on what other injector seals I could use that are slightly bigger diameter but same thickness and center hole?

 

But I can't access them to spray them, with the airbox doing that overhang. Is there a way to run the engine without the airbox on, and be able to hit them?


I tried shooting some propane gas which I thought could flow down but had no change in the engine running.

When I fished a 1/4 hose back there, attached to a funnkenand my ear, I couldn't hear any air, after adding the grease. I could hear a little air on 1 (leftmost?) until I added the grease. I can't access 4 (right?) even with an air hose, with the airbox on

 

I wish I could figure out how to upload an audio recording. It seems to me it runs slightly less rough when I spray maf sensor cleaner on them. But it seems to be all of them are needed to make a change.

I'll try what youve suggested, and report back, thank you very much!