P0133 code - How do I fix it?

[lh5w]

I have a 2001 Corolla S. It has about 160k miles on it. Right now, the check engine light is on so I took it to Auto Zone for a diagnostic. The code is P0133, heated oxygen sensor - bank 1 sensor 1. I have 5 possible causes and don't understand any of them.

1) Open or short circuit condition
2) Poor electrical connection
3) Engine mechanical fault
4) EFI relay fault
5) Faulty heated oxygen sensor - bank 1 sensor 1


A little history:

In July I noticed the "get up and go" had gone from my car. When I started the car, it didn't accelerate in proportion to the force I was putting on the gas pedal. I figured it was just because my car is old. The car only acted like this when the engine was cold.

In August the check engine light came on, and the code was P0133. My dad changed the first oxygen sensor but it didn't fix the problem. He disconnected the battery after he installed it to reset the computer. The car continued to run poorly and the check engine light came on a few days later.

Next, he cleaned the MAF but that didn't fix it. So, he replaced the MAF after Christmas. The check engine light was off for about a week when it came back on with the code P0133.

For the last couple of months, it has had the same acceleration problems and then some. At stop lights, it shudders, sort of like when a car is going to run out of gas. But I have a full tank when it does it. It has not stalled on me yet.

What else could be wrong? The probable causes on the print out from Auto Zone are really vague to the uninitiated like myself.

[leakyseals]

The front heated 02 (pre-cat) serves dual roles. One is the air fuel mix. The other is the initial reading to compare with the post cat 02 for catalyst efficiency. So it would make sense you are losing performance and likely gas mileage. The 02 sensors last with or without triggering a code roughly 100k before they go awry.

[lh5w]

Spell it out for me, is my front oxygen sensor bad? I don't understand. :-(

[Jjona5]

Is it possible he didn't put a heated(3 wire) oxygen sensor in to replace the old one? You could also have a vacuum leak somewhere causing it to run lean. Did the 98s have plastic intake manifolds?

[Jjona5]

Also you might look into either sending your injectors off to witchhunterperformance or buying a used set on ebay and sending those off(what i did to prevent down time). They dismantle the injectors, clean them, replace screens and orings, and then flow test them to make sure they flow correctly and within a certain range. My corolla runs much smoother now. I didn't really have a problem with the car but I always do this with used car purchases as they only charge about 14 bucks per injector last time I checked. When you get them back they flow as new.

[Beekeeper2020]

One thing about this type of the problem, is that it could be a lot of things.
Without sophisticated equipment to measure various component, you can try process of elimination. If you bring your car to the dealers, it will cost you an arm or a leg (~ $500).

Therefore, it is logical that you try to replace the items that may cause this issue.

Try looking into the ignition side of the system.

Renew, the spark plug wires, replace the spark plugs. Clean the injectors.

Clean the EGR, or make sure it moves freely.

At least try the obvious things until you run out of options.