mycar123

I have 1998 z71 started missing sounds like I have put I preformance cam and hard to start.I have replaced cam position sensor ,rotor,distributor cap,plug wires,plugs,bank2 position1 02 sensor. When checking cam sensor voltage checked .5 ac volts manual said should be 5.0 volts when cranking noticed would hold .5 volts for a second then would jump around like crazy so I replaced it.When coded it had 02 senor bank2 position 1 replaced it solved that issue never coded again also coded p0300 random multi cylinder missfire.If engine jumped time would it still run and if jumped time would there not be a code other than p0300 stored ?
Thanks for any advice !

EinST

Welcome to the forum. It's hard to tell the history without knowing the exact trouble codes. Anyway, P0300 itself just says cylinders were not evenly contributing to the crankshaft output. A catalytic converter damage is probable from unburned fuel. I think you should find a new shop or take it to a shop if you've been working on it yourself.

Starboy

it's hard chasing these dang codes and sensors, for sure. I have a 96 Buick with that awesome 3.8 V6, just ran the codes because of a misfire. Changed my plugs, already have new 7mm wires, cleaned coil terminals already. (I do the free or inexpensive stuff first then move the budget up when it's necessary) I got 3 codes, the generic P0300 "engine misfiring," like, I needed a code for that! I also got a P0336 code, a damaged or failed crankshaft positioning sensor. It was only $25 so I bought one and will install soon, clean my EGR valve pintle and hope for the best. What do your codes tell you now that you've cleaned up so much?