I looked at a for sale 2002 se sc today, 4600 buck, has 170000 km, it has new sc but theres a clacking noise coming from the sc, it will run but when you step on it it bogs real bad, it wont go over 20 kmph, owner says its injector, real nice ride i'ld like to buy it but i have never owned a nissan, any info on what might cause this problem? Thanks
Power bogs down and won't go over 20kph? Sounds serious... If a fuel injector went out then the engine wouldn't be running on that cylinder and would sound like it's misfiring, not exactly clicking. And 5 cylinders going would still be able to get over 20kph really easily.
I'm imagining the noise you're hearing is coming from the front of the engine to be near the sc, so you might want to look up a few of the timing belt threads here and check if your symptoms match any of those. That's a really expensive fix if it is what's wrong with it.
It's also possible for there to be a problem with the sc. If the pulley has gone out and it's no longer pulling in air then the engine would be choking and gasping for breath. It would need a whole new sc pretty much to fix that. There are very few people that I've seen who can open those up and repair them.
The price isn't bad for a vehicle that needs a few things, but I wouldn't buy it without at least having an estimate for how much it's going to cost to repair. Definitely have a mechanic check it out prior to buying so they can give you an idea of what it needs, and plan on it needing a bit of percentage beyond that.