This thing has been driving us nuts! We're slowly but systematically replacing basically every relevant part suggested by the various codes it's thrown over the past few years, but it still acts up, totally randomly.
So far, we've replaced all the plugs, plug wires, coil packs, fuel pump, and crankshaft position sensor. I also briefly replaced the throttle position sensor, to which I didn't notice any difference either, but my roommate (the owner) thought that seemed to somehow make it worse so he had me put the old one back in. We do still have the new one though, and after what it did yesterday, I might put the new one back in soon. More on what it did yesterday a little later.
Still on the menu of other parts to check/replace are the mass airflow sensor, oxygen sensor, EGR valve, and camshaft position sensor (this model does have that sensor right?)
Anyways, what it did yesterday threw us both for a loop. While parked at the gas station and idling, he pressed the accelerator pedal, and literally nothing happened, engine RPM didn't change a single bit, even when he put the pedal to the floor it simply stayed at idle.
I wondered what the hell the computer was even thinking at that moment, like did the ECM just totally glitch out then or what? So I had him shut it down, wait about 20 seconds or so, and crank it back up. And sure enough it started responding to the accelerator again, as it has been for the past few years anyways.
I'm sure that it's at least partly related to the emissions control system, as the exhaust definitely smells like it's not burning all the gas (note that there's thankfully no visible emissions, just a notable odor), but why the hell would there be a random one-off where the vehicle wouldn't even respond to the accelerator at all until shutting it down and restarting it?
We'd go ahead and jump all in and replace all the other parts I mentioned, but ya know .. $$$ .. so we're tackling things as he can afford them and as we narrow down and correct obvious issues such as a few cracked vacuum lines that I've already replaced now.
Anyways, if you've read this far, thanks for your attention to this issue. If anyone has any suggestions or advice to help us find the issue and save our sanity, we're all ears! And thanks in advance.
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I started to one day about a month ago, but I would have had to disassemble more than I expected, on a super hot day. At least I got to externally visually inspect the ECM, and at least somewhat try to reseat/readjust each cable I could.
I didn't see any obvious external water damage on any of the under-dash wires, modules or computer, but the weird left blinker ghost issue sorta changed a bit after trying to reseat the harness connectors.
I didn't manage to get to the back side of the ECM properly though, it would have taken too long and I was already starting to suffer heat exhaustion..
But you do bring up a good point, if anything, when the weather cools down and cooperates a bit, I might need to spend some more time under there and as best as possible reseat everything and inspect all the connectors.
At least all the ones I can almost readily access anyways, at a certain point it stops being worth it to chase ghosts.
Sigh, Mass Airflow Sensor and Oxygen sensor are the main things next on the menu, plus always keep an eye out for the obvious..
Best of luck, I don't think I'd be able to narrow it down without taking a look at the car IRL. I'd be interested to know what the issue was once you figure it out though :D
I finally figured it out!!! Bad MAF Sensor!
How did I figure that out? I just unplugged it. Goddamn thing is only even there for California emissions standards, we don't live in California LOL!
It runs way better with that contraption totally disconnected 👍
Thanks for the update! You seem fairly knowledgeable yourself, so I don't really want to state the obvious, but the car is now probably running in emergency mode. It's not really a emissions thing but more of a general efficiency thing, the average fuel consumption will most likely increase without the sensor. I'd definitely swap it for a new one.
Indeed, I'm sure that forced it to run in emergency mode (we tend to call it limp mode here, same difference though). That was actually the whole idea behind testing that, I mean hell we ain't got $100 to pull out of our collective asses for a new sensor on just a whim, I wanted to verify first.
We were actually out of state yesterday when I decided to unplug that, and after over 100 miles on the trip back, it didn't give any problems (aside from that stupid flaky left blinker switch), it was almost like he was driving a whole new vehicle!
Hell, even if he never gets a new sensor, it's running fantastic now! Since it's had plenty of miles running good and stable now, sometime today I'm gonna take a light sniff of the exhaust to see if that odor has basically gone away too, I figure it probably has..
Great to hear! And nice work with the diagnostics :)
I've since confirmed, practically no smell to the exhaust now. I bet just like it is now he's gonna get better gas mileage to boot 👍