I searched around but I'm not sure where to go exactly from here.

I picked up a 5-speed '98 LS coupe about a month ago, it ran beautifully when I bought it. CEL was on for what I later found out was the primary O2 sensor (wires ripped out of the socket), and the thermostat was stuck open. I replaced the thermostat, no issues there. After about 1500 miles worth of driving I managed to pull the CEL code (wiring issue with OBD port), and found the O2 sensor issue so I ordered another one. Shortly thereafter, the car started to idle and run like **** at lower RPMs and I'm getting P0301, P0302, and P1300 codes. If I get on the gas and get the RPMs up to 4k+ it seems to run fine. I've repaired the O2 sensor plug to hold me over until the replacement is here so the P0135 code is gone. I've also cleaned the main grounds, replaced the dizzy cap, rotor, and plugs with new ones, replaced the wires with almost new NGK ones off of my old teg, and replaced the fuel filter. The timing belt was supposedly replaced 15k miles ago. The engine still runs like hell and misfires on 1 & 2. I pulled the plugs again and the ceramic around the electrodes on the plugs from those cylinders are a reddish brown color while the other two are still white. No oil or any kind of deposits on those plugs.

ETA: I almost forgot, when I replaced the distributor cap and rotor the dust shield was missing and these two screws were gone:



One screw was sitting on top of the cylinder position sensor and I believe the other one was sitting in the bottom of the cap. I heard something fall but couldn't find it. I replaced the one screw then robbed the other screw and the dust shield from another dizzy.

I have to drive this car 60 miles tomorrow to get to work and I'm a little worried about it...

 

Anyone? I need to get this figured out so I can start work on the rest of the car and I really need to know if I should drive it tomorrow!

 

You have an IM. 94

 

Okay, I've been meaning to post an update to this but work has been killing me lately...

The good:
Last Tuesday I had discovered that the insulators for the plugs in 1 & 2 had cracks in them, replaced the plugs and the car was running 100% again. Very steady idle right around 750. After the primary O2 sensor was replaced I'm getting a P0420 (cat performance under threshold) every couple hundred miles which I figured would happen. I planned on replacing the cat and the B pipe anyway because they are in bad shape. The flanges are rusted out on them so much that I have significant leaks between the A pipe/cat and the B pipe/muffler.

The bad:
Saturday night I managed to get stuck in my uncle's driveway. I did a lot of spinning and threw a lot of mud/snow around. <- Not sure if this could in any way affect anything so I figured I'd add it. I immediately drove about two miles to a carwash to hose all of the crap off of my car, while I was waiting in line the car started to idle rough again and threw a P1300/P0301/P0302 code again. I cleared the code and hosed the car off, it ran fine after that until I drove to work on Monday. Pulled out from a gas station and it sputtered around a bit and threw another code. It ran absolutely fine for about another 20 miles then, like a switch was flipped, it started sputtering very lightly now and then and I lost a lot of power. I couldn't get over 3500 RPMs with the pedal to the floor. If I kept the pedal steady, the CEL would flash. If I gave it more or less fuel it would stop flashing. It did that for about ten miles then again, like a switch was flipped, it ran absolutely fine for the remainder of the trip. That's how its been running the last two days, it keeps alternating like that.

I'm taking the car to a shop on Thursday to have them put a new fuel tank on, aside from that I have a known good distributor that I can throw on to try and I can check/clean the thermostat housing ground tomorrow night...not sure where else to go from there...