The Nissan Path

hey guys, my girlfriend has a 1998 Pathfinder V6/4WD/5sp with 157k on the clock. It's having a lot of problems and we don't know whether she'd be best of getting it fixed or trading it in.

current problems:
shocks
tires
knock sensor
evap leak (i don't really know what this is, but the mechanic recommended replacing the knock sensor and fuel cap)
throttle body (sheet from mechanic says "Check coolant leak from throttle body, advise Found that the wax pellet is leaking and will need to be replaced"... broken English, I know)
transmission (poorly installed clutch)

I don't know wtf the mechanic means with regard to the throttle body. Does the whole throttle body need to be replaced or does only the wax bead need to be replaced?

How long can one of these vehicles live if maintained properly? I would hate to watch her spend all this money then have the engine require an overhaul in a year.

I'm pretty handy... I replaced the shocks on my Rodeo last year... I'm thinking that with a Haynes manual, I should be able to take care of some of the problems.

Any advice? We are poor and desperate.

shocks - typical, aftermarket ones are half the price of factory

wax kit - typical - some 98's had an intake manifold update for the elbow, but wax kit can leak forever so long as its not dripping and the cold idle drops normally after warm up

evap - could be gascap, could be cannister, vent valve, vacuum cut bypass valve, purge control solenoid valve - don't guess - it could get expensive

clutch is big $ - for labor - if it drives fine - leave it alone, i don't see how you could f-up an install on those.

at 160K YOU WILL BE DUE FOR A T_BELT!!!