Don't have problem right now, but my CEL comes on if I use anything less than premium. Code is always P0132 O2 sensor high voltage bank 1, sensor 1. Replaced the o2 sensor, but it keeps popping the CEL (Yes, I unplugged the battery to clear the codes from the computer) if I run regular or mid-grade fuel. Can run those fuels, but have to put some Lucas oil in the gas to keep that code fm popping. Gotten the code 5 or 6 times now. Replaced IAC and speed sensor as well. Has been a few months now because we just keep running the expensive fuel.

 

you dont mention which year your truck is... does it ping on the lower grades? if so check the plenum gasket for leakage.

 

Sorry, it's a 1998 5.2L and yes it pings on the lower octanes. I'll check those tomorrow. Thanks!

 

has your pcm been flashed?