Driving with a bad O2 sensor

Possible ignition module heat failure

Hello
The engine and automatic transmission in this vehicles drive train are fully electronically controlled by a computer called the PCM and TCM (Power Train Control Module, Transmission Control Module). When a problem like this or other drive-ability related problems occurs the computer stores a record of the problem (there are of course some exceptions to this, like the fuel pump, engine coolant temperature sensor and MAF sensor for instance) in the form of a fault code in its memory, to read these fault codes you must have the systems memory scanned with a special tool. Once the fault code(s) are read you then must perform the appropriate diagnostic testing to find and resolve the problem(s) DO NOT REPLACE ANY PARTS UNTIL A TRAINED TECHNICAIN HAS DIAGNOSED THE PROBLEM TO AVOID SPENDING YOUR HARD EARNED MONEY ON PARTS THAT MAY NOT CORRECT THE PROBLEM

Hi,
Upstream Oxygen sensor low voltage output bank1. Usually a bad o2 sensor. Bank 1 is cylinders 1-3-5 and upstream sensor usually on exhaust manifold. Replacement is recommended to clear the fault....Mike

The o2 sensor is in the exhaust. It is in the Y-pipe on the back side (firewall side) of the engine.

I'd instead go and get your favourite penetrating lubricant (My personal favourite is ordering some AeroKroil from Kano Labs), spray it generously on, let it soak in, and then start to try and grab it out.

I assume you asked, because you haven't looked for them, and never removed one before.
They are always in the exhaust pipe before the converter or most are in the converter.
A 22mm or 7/8" wrench may be what you need
Usually, you use a special O2 Sensor Socket,there are different ones.

Don't replace without testing first
OBD2 Codes--for O2 Sensors --doesn't mean it is bad,could be a vacuum leak.

first guess would be the fuel pump or fuel filter

My Pontiac Grand Prix is also a 99, it has 216,+ thousand miles on it, it runs great, idles good, I need to replace the oxygen sensor tho as it shuts off on me while driving or sometimes coming to a stop. You might try checking the fuel filter and pump as well.

The o2 sensors are located on the exhaust system.The upstream in on the rear exhaust manifold and the down stream is in front of the catalytic converter.Usually when they are bad they will make the check engine like go on.Make sure the air filter is clean,tires at correct inflation,alignment is to specs.If the vehicles pulls to one side or the other or steering wheel is not straight when driving down a straight stretch of road.Also tires are wearing normal.Use cruise control where ever on highway.If you let your vehicle warm up in winter.This also uses gas.Hope this helps.Good luck.

Nope, you just need more miles. When the car's computer has been disconnected from power (such as when the battery is unhooked), it'll set what are called "readiness codes" when power is reapplied. It takes a certain number of miles to clear these - some cars require 50 miles, some 100 miles, and some (such as some Isuzu models) need very specific drive cycles to clear them. Once the requisite number of miles have been driven without issues, the readiness codes will extinguish and your car should pass.