Just now trying to diagnose a new stumbling/studder problem.
This is on a 2.5L MTX.
When the engine is started cold, anything more than gentle acceleration causes serious engine bogging. This was certainly not always the case. Normally, even in artic temps, once the engine was started, it accelerated perfectly.
The problem goes away for the most part after warmed...but not entirely.
Idle is perfectly smooth. When engine is at least partially warm, I can feel a subtle stumbling occur under light to moderate acceleration. Once the secondaries kick in, it revs nicely and I can't seem to detect the stumbling any longer.
I've replaced the plugs (+4's) already - using Magnacore wires, cleaned the TB and EGR passages. EGR holds vacuum but haven't tried the vacuum to EGR to test the idle yet.
DPFE is the original one (silver).
The stumbling isn't bad, but it's noticeable and it's annoying.
