Background: bought a 2002 RSX Type-S in July. Previous owner had most of the maintenance done, though some things weren't. Car had 131k on it when purchased, now has about 133,700. Spark plugs were replaced (OEM NGK Iridium IX) shortly after purchase. Vehicle had following mods when purchased: Revo short shifter, Injen SRI.

After driving it for a couple of months with the SRI installed, I got tired of the additional noise that didn't include additional power. So, I reinstalled the factory air box/tubing that came with the car. Also reset the ECU (by shorting the disconnected battery cables to one another, as prescribed by a friend who is an Acura tech), and performed the idle relearn (idle until cooling fan cycles twice, switch off, then restart the engine). The car runs normally, or at least as well as it did with the other air intake on, except in the following situation:

When accelerating in a "spirited" fashion at/near WOT, upshifting at 7000+ rpm, the RPMs drop to about 5000 after upshifting, and the engine will not rev past 5500 (at max throttle). At 5500, it seems to be hitting the same fuel cutoff that one would encounter when trying to rev past 8200, or if you floor the throttle when the vehicle is stationary and in neutral, where it also kicks in at 5500rpm. No DTCs/MIL stored, and no other warning lights. After lifting the throttle pedal briefly, normal acceleration resumes.

So far, I've talked to a few Acura techs, but without more to go on, all they can really give me are educated guesses. It could be the VSS reading zero MPH after shifting, though my plug-in data tool does not indicate this. It might also be the VTC gear on the intake cam locking up in the advance mode and not unlocking, etc. I get the feeling from them that this is/was not a common problem with this vehicle, because if it were, most techs of their experience level would just say "replace (x) part, that'll solve it." But, none of them has, so I'm stuck with either guessing and throwing parts at it, or taking it to the local Acura dealer, who may or may not be able to correctly diagnose it.

So, if anyone's had the same problem with their car, any insights you might have for solving it would be greatly appreciated.

 

So no stored codes... and she won't engage vtec.

Does she still sound healthy? No long ticks?

 

Sounds healthy, runs completely normal otherwise. VTEC does engage, though the transition is a lot smoother than in my old car (2011 Civic Si). I'm already planning on replacing the VTEC solenoid gasket/screen, since it might be leaking, and giving the valve a good cleaning while it's off.

Also forgot to mention: Valve cover was replaced soon after I bought it, and the valve lash was checked/adjusted at that time.