← Back to list

2000 S10 4.3L 2WD P1351 Code: O2 Sensor Burned & Grounding Out After Cat Converter Replacement

Model: 2000 s10 4.3 2wd Fault Code: P1351 Posted: 2017-11-26 17:54

After barely making it home from work, my 2000 S10 4.3L 2WD started exhibiting severe power loss and rough idling, eventually triggering a persistent P1351 diagnostic code. The O2 sensor on Bank 2 was found to be burned out and grounding directly to the frame rail—likely caused during a recent catalytic converter replacement at a muffler shop two months ago. I replaced it with a spare O2 sensor, which resolved the immediate electrical short but the P1351 code continues to return. I performed a thorough diagnostic: tested coil signal (steady cycling), measured coil resistance at 7.9 ohms, confirmed stable voltage at 12.5V while running (no drop-out except for starter drag). ICM, CKP sensor, and ground connections were all within specification. To get the engine started, I replaced the ICM three times, swapped out MAF and MAP sensors (updated a month ago), replaced coils twice, changed the distributor, tested spark with new plugs (which showed heavy carbon buildup), verified engine timing, replaced the fuel filter, and had it inspected by a shop at 260,000 miles—only to be told 'that’s your problem; you need a new engine.' I immediately had it towed back. I also cut a notch in the exhaust pipe to rule out blockage. Despite all these efforts, the P1351 code persists. Recently, I swapped plugs due to severe carbon fouling and noticed fuel pump cycling on/off—new plugs show signs of being wet. This is extremely frustrating as I’ve done nearly every common repair for this issue. I’m now considering testing the fuel pump and injectors (spider injection), though no visible leaks were found in the fuel regulator. I replaced the fuel regulator five years ago due to excessive intake fuel, which was evident when removing the throttle body. I own the truck since new—only major issues have been catalytic converter failures (twice), fuel pump failure once, AC compressor, and standard maintenance like brakes and tires. I’d love to see it reach 300,000 miles. Given that thousands of solutions exist for P1351 across different vehicles, I suspect this case may have unique root causes. I’m now planning to use a higher-function scanner to retrieve additional diagnostic data beyond what my current device supports.

Related fault codes
P1351
Comments (4)
Anonymous 2017-11-26 17:57

Forgot to mention: the spark plugs were replaced after being found completely clogged with black carbon. The fuel pump cycles on and off, and even with new plugs, they show signs of moisture—this is driving me crazy!

Anonymous 2017-11-26 17:59

I dumped raw fuel into the throttle body to test for intake issues, which initially caused backfiring—but after three weeks, something changed. Now it just backfires and sounds like the muffler is submerged in water.

Anonymous 2017-11-26 18:11

I’ve owned this truck since new—only major repairs have been catalytic converter failures (twice), fuel pump once, AC compressor, and routine maintenance such as brakes and tires. I’d love to see it reach 300,000 miles. Any solutions for P1351 on a 2000 S10 4.3L 2WD would be greatly appreciated.

Anonymous 2017-11-26 19:01

Next step in my troubleshooting: testing the fuel pump and injector system (spider injection). I know the pump cycles and smell fuel from the exhaust, but it won’t start. No signs of fuel regulator leaks were found. I replaced the fuel regulator five years ago due to excessive intake fuel—this was noticeable when removing the throttle body. With so many different solutions reported for P1351 across various vehicles, this case seems unique. I’m now getting a higher-function scanner to read deeper diagnostic codes that my current device can’t access.