1A Auto: Aftermarket Auto Parts

U.S. Toll-Free Call Center Hours

888-844-3393

Espanol: 866-401-3393

Working Hours:
Monday - Friday
9:00 AM to 7:30 PM
Eastern.

Highest Ratings: Quality: We've got the awards to prove it!

We've won the Bizrate Circle of Excellence award, five years in a row. Rated outstanding for quality, satisfaction, service, and on time delivery. 1A Auto selects the highest quality parts from the best manufacturers. Check our excellent ratings.
Fastest Shipping: We ship the same day!

We'll ship your in stock order the same day, when received by 3pm Eastern. Need it yesterday? We can ship overnight. And ground shipping is always free.
No-Hassle Returns: Changed your mind? No problem.
An auto parts store is only as good as its return policy. Changed your mind? No problem. We'll take it back and credit your account in full. See full details...
USA Support Techs: 99% of support calls answered in 1 minute!

Our customer support techs are US based, car part experts. They're certified by the National Institute for Automotive Service Excellence (ASE). 99% of support calls are answered within 1 minute. View our exceptional customer service ratings.
Best Value: Pricing that's often 1/3 of dealer prices!

We're constantly comparing our prices to competitors, to ensure we're providing the best value possible. Our parts are original, high quality, and we support what we sell. There is no better deal for aftermarket auto parts on the web!
Our Guarantee: Satisfaction is the bottom line.

1A is a family owned business and our customers matter to us. If you're ever unhappy with your experience, tell us why and we'll make it right. Live help is available by phone or email.

Home > Ask The Experts

Question Reply

Customer Question:

When they scanned my car, the error code said it was “Bank ‘X’, Sensor ‘Y’”. What does this mean?

1A Auto Replies:

In order to read and diagnose oxygen sensors correctly, the computer gives each a sensor a specific name based on its bank and sensor numbers. Bank refers to the side of the vehicle that the oxygen sensor is on. Bank 1 refers to the side of the motor on which cylinder 1 is located. If the engine is a four cylinder, there will only be one bank. If the vehicle is a six-cylinder or larger, Bank 2 would be the located on the opposite side of the vehicle from Bank 1 (ex. Bank 1 would be on the driver side while Bank 2 would be on the passenger side). The sensor number refers to the order in which the sensor is located from front to back of the vehicle. The sensor closest to the front of the vehicle would be Sensor 1.

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1A Auto Parts is a Circle of Excellence Fifth Time Award Winner!

About 1A Auto

Welcome to 1A Auto! We are a family owned business, and for the last 50 years, we have been using the same high quality aftermarket replacement auto parts that we now offer for sale online.