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2002 Chevrolet Silverado P0140 O2 Sensor Issue: Miss in 5th Gear at Low RPM?

Model: 2002 Silverado Fault Code: P0140 Posted: 2007-12-02 14:31

I own a 2002 Chevrolet Silverado with a 4.3L V6 and 5-speed manual transmission. The Service Engine Soon (SES) light has been on for some time. While the truck drives normally, I occasionally experience a misfire or 'miss' when shifting into 5th gear at low RPMs—such as around 50 mph. This miss does not occur during gear changes or at higher speeds. The diagnostic trouble code displayed is P0140: Oxygen Sensor Bank 1 Sensor 2. Is this code directly related to the misfire I'm experiencing? I plan to replace the O2 sensor located on the driver's side, between the catalytic converter and muffler—does replacing it resolve the miss issue, or are these symptoms unrelated? Thanks for any insight, Jason

Related fault codes
P0140
Comments (6)
Anonymous 2007-12-03 08:26

It's difficult to diagnose accurately over text alone. Please consider additional diagnostics if possible.

Anonymous 2007-12-03 11:58

I replaced all spark plugs and plug wires as well. The misfire occurs in all gears, but is most noticeable when driving at steady low RPMs—especially in 5th gear. It doesn't happen during gear shifts, but if I'm cruising steadily at lower speeds, the engine will miss intermittently. The issue can be sporadic: sometimes it goes days without occurring, then suddenly misses several times within a single day.

Anonymous 2007-12-03 13:28

I recommend checking and replacing the distributor cap and rotor—these components can contribute to misfires in older engines like this one.

Anonymous 2007-12-04 23:28

Thanks for the tip—I'll try that. Also, is the O2 sensor Bank 1 Sensor 2 located on the driver's side between the catalytic converter and muffler?

Anonymous 2007-12-05 09:16

Yes, that's correct—the P0140 O2 sensor is indeed positioned on the driver's side, between the cat and muffler.

Anonymous 2007-12-05 12:03

Appreciate the help!