Is it bad to drive with a faulty output shaft speed sensor circuit?

My transmission light came on yesterday so I did a code check and got the code P0720 and P0722 meaning the speed sensor is not working properly. Is it harmful to drive the car with it malfunctioning? I drive a manual transmission 2001 ford focus, I haven't noticed any change in the way the car drives or shifts.

2000 Ford Focus Overheating

I have an 2000 Ford Focus Automatic. It recently started overheating about 2-3 days ago. So far what I've done is replaced the thermostat and filter. I also drained the hoses and added water. I went to AutoZone to purchase an radiator relay, but ultimately didn't need it because both of the fans are working properly. Any suggestions?

2006 Ford Focus Battery Light On and Off?

I have a 2006 Ford Focus and the battery light has been coming on and off for the past 8 months. I'm going on a long road trip so I feel I really need to address this issue. I had my battery, alternator and started check and they are all fine. Also the light comes on for what seems like a every 20 minutes or so for a couple of minutes. Another thing is that I feel like it starting happening after getting an aftermarket stereo installed.

Which of these small cars do you think is the better choice?

These may not be the most popular choices but I'm considering these three because they are my favorites in terms of styling compared to other competing cars.

2008 Ford Focus
2007 Nissan Sentra
2007 Mazda 3

I'm looking to buy used obviously, and most likely high mileage to save money, anything from 90 to 120 or so and specifically the year model body styles mentioned. All 4 door, 2.0l, automatic versions.

The Mazda is the "oldest" design of these cars and the only slight issue with that is no standard side curtain airbags on most of them, and the stock audio only supports CD (I think). The Focus was new for the 2008 year and that usually means more bugs that need worked out over all. The Sentra has the least issues reported on the CarComplaints website, but it's also the biggest of the three cars so I'm curious if the ride feels any different, or if that makes the car any more sluggish than the other two (power is NOT a priority).

I'm wondering how these three cars compare as for as reliability, cost of DIY repairs, handling, and just best value for the money.

EverStart battery replacement?

I used car about 6 months ago and the battery keeps dieing. I've taken out my aftermarket stereo and my phone charger and all that to see if it was draining the battery, but it died again last night so that wasn't the problem. The alrernater and battery were both replaced about a year ago so I didn't think that was the problem but now I'm pretty sure it's the battery. The battery is and EverStart Walmart battery and it says it had a 2 year warranty on it. But I don't have the receipt, and the previous owner bought it. Not me. But it has a date on it, and it's only been about a year since the date it says it was put in. So will they replace it if I bring it to the store? I have a 2002 Ford Focus ZTS with 150k on it.

Does nearly every automatic car have kick down button?

I have a Ford Focus 1.6 zetec 2013 powershift, and I don't have the kick down button or cable when I press the accelerator? Is this normal, does every automatic car have that feature including the new ones that are available?