Worked on the Gen2.5 a little bit this weekend. Make sure the coolant level was 100% topped off (haven't flushed yet, was busy working on a friend's Miata), then started to investigate my exhaust leaks, which i believe were causing the CEL for the cat. Flange between passenger manifold and y-pipe was backing off. Cranked it down a few turns, and the noise is a bit better. No other serious leaks exhaust-wise through the rest of the exhaust, just a couple pinholes from some pretty awful welding. (Truck has a custom junkyard-spec exhaust south of the y-pipe. Sounds good, looks bad.) Cleared CELs, haven't driven much since then, maybe 10 miles, but they haven't come back.
Unfortunately, i learned three things:
1) Passenger manifold has a big nasty crack in it.
2) Valve seals are in pretty poor shape. Looks like it's burning (maybe leaking, hard to tell with the oil all over the bottom from my oil filter mishap) to the tune of about 1 quart every 1000 miles, and the truck stinks. Burning oil smoke coming from passenger manifold means there's often smoke wafting out of the engine bay, and even sometimes up into the cabin. Going to take care of the manifold and valve seals this month, but beyond that i don't think i'm going to invest any more time or money into this engine, since it won't be sticking around.
3) Transmissions seems to be leaking slightly and/or PO didn't fill it up properly. Going to dump another quart in it and monitor.
Other work i did:
1) Removed CD changer. Surprisingly heavy.
2) Swapped factory head unit for a Kenwood Excelon KDC-X998 (and learned that i have a blown tweeter on driver's side, and door speaker on passenger side). A bit annoyed with the design of the console bezel on this truck. Can't fit the trim ring over the headunit like it should have. Will figure something out when i get my parts to do an interior swap, as my bezel is cracked at the top anyways. For future radio plans, going to try first fixing the blown speakers with factory replacements and adding a 10" sub to take the low load off the factory speakers and see where we are. If i don't love it, i have some nice 6.5" components hanging around that i can swap in, just have to decide if i want to try to power them off the factory infinity amp or just gut the whole thing and start fresh.
3) Removed rearmost seat belts. I don't have the 3rd row seating, and will not be sourcing it.
4) Washed it. Immediately had mixed feelings. It looks better clean, but not as "tough." And this is one of the most "pinstriped" rigs i've ever seen.