Justin Gaznick

I bought the car a couple months ago and drove it 400 miles without an issue and now I have one. Car gets stuck in open loop and I get an OL Fault reading on my scanner with a P0300 random misfire code and an open injector circuit code. Originally I had a cylinder 5 misfire from a single open injector which I had replaced and it ran fine for about 50 miles, now its running rich and smells horrible.P0300 and P0200 are my current DTCs. I did get a heater circuit O2 sensor code as well but after clearing it, it came back one more time and haven't seen it since.I removed the alternator yesterday and had the voltage regulator/ alternator tested and its getting 100 amps no problem, guy said its working fine and not fluctuating. Reason I had that checked is that all my lights have been pulsing and my voltage is almost reading 18 volts and drops to around 16 and bounces around occasionally after driving (when I could actually drive it). I figured maybe my coils weren't receiving the correct voltage and causing a random misfire. Apparently I was wrong because the alternator works fine? It was previously rebuilt and is an aftermarket alternator. Im at the point of just buying a new alternator even though supposedly this one works so I can definitely rule that out as a problem. As I was removing the alternator I noticed the exciter wire had been spliced (very poorly) so I have to resplice it and try that as an option.The car ran great for 400 miles why would it randomly have this many misfires and and open injector circuit? Im getting overwhelmed and don't know where to begin to get to the bottom line. Btw car seems to run good in extremely cold weather and after it warms up misfires happen with fuel getting dumped into the engine. OL fault grrrrr somebody give me some insight! Much appreciated in advance!

ss.slp.ls1

iTrader: (36)

Seems like you run fine with the car in speed density and once the car warms up and operates in closed loop then your troubles present themselves. After it warms up is when the car starts to use the oxygen sensor and MAF sensor data to change the injector pulse width. I would check all of the wiring to the MAF, o2 sensors, coil packs, and injectors. It seems like you are having a wiring power or grounding issue that is causing all of your problems. Check the harness and connections for burns or tears. Check all grounds including the grounds on the back of the cylinder head. Checking the fuse blocks for burnt fuses won't hurt either.

Justin Gaznick

Thanks for the quick reply SS, I was also wondering if a broken CAT could cause this issue, Ive been hearing an awful lot of rattling on my bank 2 side and Im just trying to be as informative about my problem as possible.

ss.slp.ls1

iTrader: (36)

I have heard of a clogged cat causing a laundry list of problems, though I have never experienced any of that. For some reason I don't think that is the issue. If you only had a P0300 code, then you could have many reasons for a random/multiple misfire. However because you have a P0200 and had an oxygen sensor circuit code, that leads me to believe you have a wiring issue. I'm hoping that it's just a simple grounding issue.

Justin Gaznick

So after constantly hunting wires and checking injectors/ multimeter tests I found the issue! It was a pcm wires that rubbed against the hood lip and was grounding itself to the car. Ironically I happened to find the problem on my birthday which was the best present haha. I also took the pcm out and cleaned all the pins with an electrical cleaner, they were heavily oxidized and not looking good at all. I have some pics Ill post from my phone and you can see yourself. Just glad to have fixed it and if anyone has this issue hopefully this info will help! Thanks again SS appreciate the input and help