2009 Elantra P2195, P170, P0300, P0301, P0302 etc
Hello guys, I'm trying to diagnose my wife's 2009 Elantra with the 2.0 Cali emmissions, and not having a lot of luck. Here's the story: she left to go fuel up, and then go to work Thursday morning. 1.5 miles after filling up, she was accelerating after a stop light when the car started changing engine speed (she could hear it rev, and the RPMs went to 4K), without any increased throttle input on her part. Then it started stumbling, and acting up, and couldn't accelerate. She pulled off the road and called me. I scanned it, and it had a P2195 and P0170 (O2 sensor signal stuck lean B1S1, and fuel trim B1) and I think one other very similar code. I cleared the codes, thinking it might at least get the car running normal enough to get it home but it didn't have any impact. The car could not accelerate, and could only barely move, which my initial read was limp mode.
The car starts, and idles relatively ok, but if you try to rev the engine at all it bogs down (but typically doesn't stall, but has a few times). The next day when I tried to figure it out, it was idling, and started to stumble pretty hard, whole care shaking kinda deal - it was misfiring. So it then threw additional codes for general misfire, and misfire in every single cylinder. So I go to work on checking what comes to mind. The fuel pump primes and turns off as it should, but I know that doesn't mean it it's delivering the proper fuel. I pulled the output fuel line off, and it pumped about 5oz of gas into a bottle with turning the key to the on position 3 times (priming). I had no way to check fuel pressure (doesn't have a valve to make things easy). I tested the upstream O2 sensor, and the ohms were higher than spec, but I may have done it wrong (I unplugged it and tested the wires in the harness, but maybe it needs to be plugged in?) I tested the MAF, OCV, IACV, ECU harness, fuel injecters, spark plugs and wires, ignition coils (which I may not have done properly either), and probably other stuff. I replaced the plugs and wires, they all have good spark when grounded. Everything checked out, but I cleaned up the the grounds for the battery, and ECU just to be sure. It idle's a little better, and I can now rev it to 2800 sometimes, and then it bogs down, I try again and it goes to 2650, then again, it goes to 2450...
I got a little desperate, and threw in a new O2 sensor, but as you would expect, it's not that, it's actually running lean, like it says.
I'm wondering what people think about a situation like this? Could it be bad gas? Could something be plugging a fuel line, or the filter be plugged? I wish I knew more about motors, and the vacuum system. I don't know where the vacuum lines are to look for leaks. Pointers, or a diagram would be awesome! I don't know much about Hyundai, or what these cars tend to have for issues. It just seems odd that it was running fine, then went into a seemingly Limp Mode, and has not recovered.
The live data I can get shows both O2 sensors temperature raising exactly in sync with each other - so I'm assuming that means it's not a plugged cat, but I maybe I'm reading to much into that. The AFR mixture being called for, and what it's metering are usually pretty close, but the metered reading does fluctuate, which I think is normal. Vacuum runs between -14-18 in/Hg. Evap pressure ...I'll just upload a picture of it at idle, and one of it when revved to 2800!
I hope someone can help! I did bite the bullet yet again, and I have a whole new fuel pump assembly that should be arriving tonight. But I'm worried that it won't be the problem. Take care guys, thanks for reading.