I worked on a friend's 1998 Chevy Tahoe - his dad took it into Midas and a hack job local shop for new cats and cylinder heads a while back - truck was losing coolant and I saw lots of Dex-Sludge form. The hack job shop replaced the heads but didn't use the newer Fel-Pro PermaDryPlus LIM gaskets. I replaced those and I got the truck to fire up on the first try. Of course DTC P1345 - cam/crank correlation was set and I did replace the knock sensor with an aftermarket one. Last week, he said the truck was feeling sluggish and he could smell gas - misfire. I pulled codes, and I saw a P0326 DTC show up along with the P1345. I finally figured out how to get TorquePro to show the GM CMPRET PID to get the engine "re-timed" and we retimed the motor at Costco's parking lot - we needed to get wiper blades, go figure. The truck was finally running smoother.
And then on the drive home, I saw the CEL turn on, then turn off. A mile later it flashed and I knew something was wrong, ECM logged P0302 and P0304 - but the knock sensor P0326 DTC was gone! Turned out whoever replaced the heads or the plugs and wires routed the #2 & 4 wires against the exhaust manifold. I replaced the passenger side bank of wires and the CEL was off after 2 miles of driving - I assume the misfire monitors didn't pick up anything. He ordered AC Delco's professional line, the wires I pulled were Prestolite, they looked the same.
My question is - could a shorted/burned plug wire send stray voltage through the engine block and cause the ECM to think the knock sensor is going bad?
And then on the drive home, I saw the CEL turn on, then turn off. A mile later it flashed and I knew something was wrong, ECM logged P0302 and P0304 - but the knock sensor P0326 DTC was gone! Turned out whoever replaced the heads or the plugs and wires routed the #2 & 4 wires against the exhaust manifold. I replaced the passenger side bank of wires and the CEL was off after 2 miles of driving - I assume the misfire monitors didn't pick up anything. He ordered AC Delco's professional line, the wires I pulled were Prestolite, they looked the same.
My question is - could a shorted/burned plug wire send stray voltage through the engine block and cause the ECM to think the knock sensor is going bad?
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