Had a weird azz'd, car-guy problem w/my winter-beater-DD'r.... so potential learning moment for folks....and interesting coincidence at the least:

'95 Subi. 226k miles. Runs like a champ...for what it is. Changed the timing belt, WP, pullies, etc as part of PM. All went well. Car started right up, ran well, drove it out of the garage, down the road....no problem. Hit the on-ramp to I-80, and put the throttle into "Driving mode" (WOT in that car! ) and....wha....tha... From about 3500 RPM up, it had no ***** at all! The higher you rev it, the worse the power deficit was. I have "poor man's dyno's" all around me; mountains + speedometer and I have 6-7 years of experience with this car, doing "dyno pulls" on these hills. One hill, in particular, I can climb at 50+ mph in third gear...every day. Now, won't get to or maintain 40. The other hill, 80 mph and accelerating(if I want to push it), in 4th gear, now won't barely get to 70. Barely. Or it might not even get there.

I was convinced the cam timing was off (advanced a tooth) -the car literally went from running great to running terrible and what'd happened? I'd changed the belt. BUUUTTT the marks all line up. I triple checked 'em when I did the belt swap, spun the engine over and re-checked, all was good. Still, it ran weak so I pulled it all apart and checked again....ALL marks lined up as they should. This ain't my first timing belt -and not the first on this car, either. No, the timing belt wasn't off, although the symptoms could have matched that problem; no top end power, lots of induction noise at high RPM/WOT, not throttle responsive above 3k. But, I knew the marks were on, and I knew the pulleys hadn't moved when I changed the belt. So.....what else kills top end power?

I had a hunch, so I ran a quick test; one that I've done before with conclusive results. I pulled the front O2 sensor, and screwed a compression tester hose into the bung, then slipped a long rubber hose over the end of that hose, and ran it into the car....and I hooked a fuel pressure gauge to it. Fired it up, matted the throttle in neutral....




....saw a peak of 22 PSI. BAM. THAT is the problem, and it was pure coincidence that the symptom started at the same time that I did the timing belt! Sonova!

I dropped the exhaust and separated the cats. Now, if @Fast355 sees this thread, he's going to be devistated that I didn't use goat **** on the rusted, 30 year old exhaust flange bolts! Nope, I committed a master tech faux pas and just used boring old HEAT to get those rusted, stuck nuts off...and....it worked!! Whaaaa??.....






Got that front cat apart and found this on the inlet side....



DOH!! ^That^ don't look right! Here is the outlet side....




...and there was my "timing belt problem".

Rodded that out, slapped it back together and got my ~40hp back. Hope this was an interesting read for other Rocky Mtn area members. Remember, when diag isn't making sense, think to yourself: "Something is going on here..." Start looking for other likely possibilities.