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willyb
11-20-2009, 07:48 PM
i have a honed out cat. and one of my o2 sensors is bad would that kill my gas milage? and how many o2 sensors should my truck have? its a 99
bank 1 sensor 2
thanks

hskr
11-20-2009, 07:50 PM
Replace the O2 sensor, and instead of putting it back into the exhaust, just zip tie it to the frame rail. But a post cat O2 on the '99s shouldn't cause gas mileage problems.

willyb
11-20-2009, 08:02 PM
do you know how many sensors i should have

got_torque
11-20-2009, 08:05 PM
I want to say that bank 1 sensor 2 is the sensor directly in front of the cat. Bank 1 sensor 1 is in the down tube, bank 2 sensor 1 is in the other down tube and 1 after the cat. Pretty sure anyway.

You should have 4 sensors.

hskr
11-20-2009, 09:45 PM
Yep, should have four sensors. One in each down tube, then one before and one after the cat. Not sure exactly how they are labeled in the PCM though to trouble codes.

LITNGETR
11-22-2009, 11:34 PM
1/1 driver side down pipe, 2/1 pass side down pipe, 1/2 pre cat, 1/3 post cat

bwdakrt
11-23-2009, 09:39 AM
Bank 1 = Drivers side odd numbered cylinders
Bank 2 = Passenger side even numbered cylinders
Sensor 1 = Before cat
Sensor 2 = After cat