Oxygen sensor Where is the oxygen senor ? 2003 GMC serria 1500 5.3 Liter engine

If the oil dipstick shows good oil level, the problem is usually is a failed pressure sensor, which I would have checked ASAP at a shop. If the oil level is very low, top it up, but to avoid serious engine damage you may need to have it towed ASAP to a shop for repairs.

Check faulty egr

What size engine does your Sierra have?

Usually, this code points to a bad catalytic converter but not always... since the rear (downstream) oxygen sensor could be bad (this is the O2 sensor after the catalytic converter).

under the intake plentium right in the middle of the valley between the heads. bad for wires getting corroded and rusted. it holds water in the knock sensor holes, you can buy the harness

Several things can cause this problem, cracked distributor cap, old ignition rotor. Or if you have coil packs, cracked coil pack, ignition control module, crank position sensor, cam position sensor. Coil pack parts and sensors can be checked by autozone, cap and rotor will have corrosion on the rotor, however a small crack in the distributor cap can be next to impossible to see, replacement is usually best option.

60 thousands

could you buy a rear end at an auto wrecking yard?

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 four on this truck. bank one sensor one is "black and white" b1 s2 "brown" b2s1 "light green" b2 s2 "red/white" good luck post as fixed thanks