I have a 1997 Ford Ranger with a 4.0L 2WD. The check engine light just turned on with a code of p0133. I know that this is something with the bank 1 sensor 1. I tried doing some research and I think that it is on the passenger side before the cat converter. Now, I don't know what to do from there. How do I go about fixing this? What part do I need? How do I fix it?

Thank you,

Barry
(vehicle rookie)

 

P0133 = Cyl bank 1 O2 sensor 1(before cat converter sensor) has slow response, means the passenger side O2 sensor switching voltage output to the computer is slow to respond to changing O2 levels in the exhaust gas, so this will affect how well/fast the computer controls that banks fuel trim/air-fuel ratio.

So that O2 sensor is probably getting old & slow/lazy with age, sorta like me lol. If the upstream/before cat converter O2 sensors have 75K miles or more of service on them, its time for them to be replaced. Both driver & passenger side upstream O2 sensors should be replaced at the same time, so that fuel trim remains balanced in both cyl banks. Lazy O2 sensors can cause driveability, mpg, & rich running cylinders, ect problems, so its best to replace both cyl bank up stream O2 sensors when we get this code. I just did this on my 94 Taurus last year when I got the code.

If you don't have one, most autoparts stores have a special O2 sensor socket removal kit available in their "Loan-A-Tool program for a refundable deposit, its worth checking out.

Use a good quality high temp anti-seize compound (Permatex-Loctite makes a good one) on the O2 sensors threads before installation & to prevent sensor contamination don't get any on the sensor end.

Let us know how it goes.