99 W900 KW 3406e cat

That I'm not sure of. Call cat and see if they use same part numbers.

 

No that won't affect fuel pressure it will just intermittently act up when they start going bad. I'm betting its a restriction, injector, injector o-ring, or that check valve.

 

Is more smoke coming out if the stack?

 

Ok you may be sucking air in the fuel sone where, ot have a bad injector

 

I have a 2000 pete with a 3406E. Only time my fuel pressure goes down is when my filters are starting to get clogged, if I got bad fuel some where. But the more I think about it it cold be a restriction some where

 

Yes, the ejector has two parts. The electronic side and the mechanical side. There are two good ways to check the mechanical side. One is a cumputer injector cut out test. The second, use a infrared heat gun, they sell they at harbor freight for maybe $10. Check the exhaust manifold temperatures for each cylinder