1999 GMC Sierra 5.3L knocking sound around Catalytic Conerters? ?
I've put in new Catalytic Converters, 2 new O2 sensors...and new Knock Sensor w/ connector...but still shows up knock senor low input trouble codes and Bank 1 Sensor 2 oxygen sensor ?
Fuel pump makes a loud humming noise, and bout to replace the A/C Compressor...
What could be the problems if you could please explain to me thank you whoever??? And where exactly is this Oxygen sensor located on the Bank 1 Sensor 2...after the driver converter or before or on the passenger side ?
Re: 1999 GMC Sierra 5.3L knocking sound around Catalytic...
On my gmc i have 2 knock sensors and im not possitive if you have two or not under your intake mani but when i replaced both mine i got the same code of low input so i took the small needle out and wire brushed it clean and also traced and ran a new wire just to be safe and that solved my problem. as for bank 1,2 if it helps any my bank one is located engine side driverside and bank2 is engine side passenger side and 3 and 4 are underneath bed side. but you can see the sensors if you look real close near the headers. hope this helps
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you have to know how works knock sensor.PCM supply 5V or 12Volts then if there is engine noise resistor raise and voltage drop.With scanner read knock sensor data while engine running you should see advance timing going down and knock count data
I would want to see the actual codes, but if it is one or two cylinders you could have a failing injector and it not show up as a trouble code. If one of the injectors is failing it can have a high resistance and affect the other injectors in that circuit. The O2 sensors and cat would not affect a power loss in one or two cylinders, and the O2 sensor codes would be present. The knock sensor only measures vibration, so it was probably ok before you replaced it. There is a chance the cap is shorting out internally which would be tough to see, and the optic sensor in the bottom of the distributor could be causing problems too. Some of the cylinders may not be firing when you think they are.
knock sensor problems arise from ---wiring --poor connections --knock sensor----insecure KS--KS incorrectly tightened ---wiring short to positive --wiring short to ground ---ECM
as you can see , there are more causes than the KS itself so care should be taken in the installation, tightening , wires and make sure that the area is water proof
Changing knock sensors on 2001 GMC 1500hd 1. Remove the intake manifold. 2. There are 2 sensors located on a plate under the intake manifold. These are the knock sensors. 3. Remove the wiring harness assembly from the knock sensor. 4. Install the new rear bank knock sensor and tighten to 15 lb ft.
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P0136 indicates a bad O2 sensor. This reports poor emission performance back to the car's PCM (computer) P0325 indicates a bad "Knock" sensor which would adversely effect drivability as far as performance is concerned. Only way to fix these 2 problems is replacement of the 2 components.
the knock sensors are located below the intake plenum,or,upper intake manifold as some call it, they screw into the lower intake, the front one is sensor 1, the rear is sensor 2. it is wise to change both if you have some miles.since you are going to be buying a gasket set to do this job.the sensors are cheaper than the gaskets.