What should I do first?

Just got myself a lovely 2000 4Runner SR5 with 199K miles. Check engine was on when I got her, but we confirmed the code (upstream O2 sensor) and that is getting taken care of tomorrow.

I want this vehicle to last and I plan on slowly adding some off-road upgrades. The previous owner took good care of her and had recently replaced the rear shocks, cat-back exhaust, plugs, wires, dist. cap, and battery. Frame is in excellent condition with only minor surface rust. Interior is immaculate. Exterior as well. Rear diff has some surface rust, but we're gonna take a wire brush to that and get it cleaned up quick.

So my question to y'all is what should I take care of pre-emptively? My mechanic friend suggested diving into the CV axles and steering components, but I'm wondering if there is engine/transmission maintenance that I should consider taking on first.

Thanks!

 

Checking fluids; antifreeze, front and rear diff., trans., transfer case, drain and replace if necessary. Also checking for any leaks or weeps, and like your friend said checking the CV's and steering. Brake fluid and brake pads/brake shoes. She's 20 yrs. old, probably needs a little TLC.

 

Welcome to the forum.

 

I would replace all fluids unless you know as fact that they were replaced recently. Also front shocks, steering stabilizer if you have one, belts and hoses. Also find out when the last time the timing belt and waterpump was replaced. And finally welcome.