Hey guys, okay here's the deal:
103,000 miles on the car and over the past few months have been having issues with a rough idle that were seemingly resolved by a simple battery terminal replacement. The terminal being loose was throwing the computer off.. or so I thought, because the car was running like an absolute DREAM for a week or so after replacing it. Well, a couple of days ago, while driving less than 45 mph in traffic, I get a SES light and the rough idle issue again. This time, though, the issue seems worse. RPMs were going anywhere from 300 to 1700 at idle, and the car would badly jerk during acceleration. So, I pulled the car over, checked the oil blah blah blah and no issue was glaring. I get back into the car to drive it home, put it in reverse, and it goes dead, but then cranks right back up and I was able to drive it a few miles to the auto shop. It seems like the ride is just getting rougher and rougher with every red light I have to stop at, and the SES light is still on, solid. Well, I get the auto shop, they check it, and it is throwing a p0300 code, random misfire. I go back to the shop today to drive the car over to my place (within 1 mile of the shop) because I plan on fixing the issue myself, and the car won't start. The engine turns over a couple of times, but won't start. Any suggestions on where I should turn my attention? I don't know where to start!
Thanks in advance,

Vince

 

Perhaps low fuel pressure. Check the fuel pump

 

Nice, thanks for the quick reply.

 

Which battery terminal was replaced? Are there any codes other than P0300? Where are you located?

 

It was the + terminal. P0300 was the only code, and I am located in Mobile, AL. Also, I'm late posting an update. Turns out, the reason the car wouldn't crank is because the auto shop drained my battery somehow. After a quick jump, the car cranked right up and has been running perfectly ever since. It's strange. I have no idea what's wrong, but I know there's a problem. I'm intermittently loosing voltage somewhere and it's causing the computer to go crazy

 

Any update on this? I've had the p0300 code for a couple months now and havent found the cause. Only difference I notice lately is that it idles a little higher then usual, like 1000 ish rather than 7 or 800. Other than that it seems to run fine. I've reset the ecu and the code goes away for a while then comes back. Tried resetting it again and now it comes back instantly. Next step might be just replacing the MAF sensor.

AG

 

Interesting that you mention the shop draining the battery though. I took it to my buddy's shop a while ago to try and diagnose it and when they went to start it up again to give it back to me the battery was dead and they had to jump it. I don't know if they left the lights on or something but even still I don't see how it would completely drain it within a couple hours. Again I haven't had any issues myself starting it, but the possibility of a battery issue remains.

 

The ecu will raise the idle to about 1100 when you throw the p0300. I used the torque program in "test results" mode, and if you let it scan long enough it will tell you which cylinders are misfiring and a misfire count. On my car I was going lean and 1 3 5 were missing. I ended up replacing both bank 1 and bank 2 afr sensors upstream of the cat. That cleared my misfires and lean condtion. My problem was the misfire couldn't be felt, but the computer would throw the code, and if not cleared had an annoying idle issue, and of course the damn light. I suggest getting the torque program, and Bluetooth adapter, and learning how to read it all, and data log as you drive. I actually found my own problem after nissan couldnt. It's great software and will save you lots of time.

 

Would most obd2 connectors have that function?

 

Yes, as far is I know. My Bluetooth obd2 adapter has worked so far in every obd2 system I have used it in.

 

when was the last time you did a tune up on the car?