If you are in California or some other state with strict emissions laws, part of the deal should be that the owner takes the car and has it emissions tested. If it passes, you buy the car and pay for the emissions test cost, if any. If it does not pass, walk away from the deal. For a mechanically inexperienced owner, emissions related problems can be difficult and expensive to fix. Some states will not title or issue license plates to cars that cannot pass emissions testing.
Keep in mind that states with strict emissions laws may make the go faster goals more difficult to reach. Some parts are OK to replace with aftermarket parts and others aren't. Check carefully before you get out your wallet and buy something you can't use in the area where you live.
Things that break often:
T5 5 speed manual transmission (syncros go bad, mostly 3rd gear)
TFI Module (Thin Film Ignition module - mounts on the distributor)
Electric door locks (see the link in my sig for a cheap & easy fix)
O2 sensors(oxygen sensors) They are good for about 60,000 miles and start to go
down hill after that.
TPS Sensor (Throttle Position Sensor) causes flaky problems with idle & acceleration.
Fog lights They overheat the wiring and cause the headlights to flicker. The fix is
cheap and simple if you can do electrical stuff.
Harmonic Balancer – they separate between the hub and outer ring. A harmonic
balancer puller is a must have to change it. You can rent or borrow a puller from
most of the larger auto parts stores.
Things that don’t break often but are hard to fix:
Water pump mount bolts – they corrode and shear off when you try to change the
water pump.
Rear oil seal on the engine – lots of parts to remove to get to a $20 seal.
Power steering pump – the pumps are noisy and the pulley requires some special
tools to remove and install. If you have the tools, they are easy to do. Again, the
larger auto parts stores will rent or loan the tools for the pulley.
Power Steering rack - it is hard to get the toe in set so that you can drive the car
to the shop to get it properly aligned.
Starter – the top bolt is hard to get a socket on if you don’t have the right combination
of socket, universal joint and extensions.
