Toyota Repair: 96 Avalon pulling to left during acceleration, cv boots, toyota avalon

Question
Test drove a 96 Avalon as possible car for my son.  The car has 138000 miles
on it and the typical blemishes for a car its age. It drove very straight coasting
and normal acceleration but had a noticeable pull to the left when I punched it
to the floor, or close. Is this a tranny or axal problem?  Also the check engine
light was on to which the owner said she thought that was fixed ( O2 sensor is
what her mechanic said)

Answer
Toyota Avalon is a nice car, but the come with a V-6 engine. Personally, I'm not a big fan of Toyota's V-6 engine. The car you drove has high mileage for a V-6. I'm sure that there's plenty of life left in that engine, but it will start to use oil through the valve seals. Very typical for a V-6. The problem you noticed about the pulling to the left (drivers side) could mean a few different things. If it was a problem with your axle or "half-shafts", you would notice a "clicking" sound as you turn corners or accelerate. Additionally, you would most likely see leaking grease on the outer portion of the CV boots. I seriously doubt that it's a trans problem. You might want to check tire pressure and front end alignment/shocks. If she has a faulty O2 sensor, ask her if the car ever had a broken head gasket.