Misfiring badly......throwing codes

[scooter9715]

My 98 S10 has a 96 motor that had about 60,000 on it when I bought it. Then suddenly it starts having this problem I call trailer pulling disease. I will be driving going in between 55 & 65 and this truck just tugs and pulls like it is towing a trailer loaded full of moving animals. Got to codes O2 Heater Sensor in Bank 1 Sensor 1 & Multiple Misfire (but one night it was not wanting to make it to 50 and when I got it coded it actually said in the 4th cylinder). This truck almost has complete tune up oil, oil filter, fuel filter, cap & router, plugs, plug wires, coil, and a new sensor in the front on the passenger side which we thought was bank 1 sensor 1 but was told thats one the drivers side. It was gotten better with the jerking but it still has that slight movement and you can just see the RPM gauge bouncing when it happens. Lately the stinkin light just flashes almost the whole way home from work. And I have to tell you it really only starts acting up when I get off from work and am driving it home which is at 11 pm. I have let it sit and gets to its temp and it still does it. I think it was playing games with me when one night I was following someone going a steady 55 and that light was a flashing but when I got it up to 60 get stopped flashing but when it got back down to 55 it started again. My dad says I'm crazy but he does not drive it at night and does not know what it feels like. This weekend we are changing the other senor on the drivers side and will see if that helps but after that I am clueless. All I have done is put manoy in this truck and its money that could have gone to get it looking good but I told myself I want it running good before it looks good. The guy that had it before me trashed it. Sorry for this long post but I need all the suggestions and help I can get. If what we do this weekend does not work I will have to settle and my dad does to we have to send it to a mechanic or sell it. My dad and pretty much fix anything but this truck has got him stumped.

[Sparky2263]

The O2 heater code won't cause your problem. But yes, Bank 1 is the drivers side. Replacing the sensor on that side most likely will get rid of the code. If you still have the old one from the passenger side, I'd put that one in first.

The difference between a flashing light and just on solid is the nature of the code. If it's bad enough to screw up the catalytic converter, it will flash. A dead miss will cause it to flash. So, something is going on with the tune-up you did (most likely). The cyl 4 code is a ggod place to start. Take a real good look at #4 cyl. plug and wire. Also, make sure the cap didn't get any water in it. Quite common. Could be a clogged injector (also quite common on a 96 engine) but it sounds more like an ignition miss.