Weird noise and shaking, pls help
Car: 2003 Ford Crown Victoria LX, 98k miles
Situation: So yesterday morning around 6am I noticed that my car was running a little bit rough. I checked the codes and had a new code, P1131 (lack of HO2S11 switch, sensor indicates lean). I also checked the oil and it was low (it's been about 2k miles since my last oil change), so I topped it up. This didn't fix the problem though, and the car was still running a little rough.
I have a BlueDriver Model LSB2 code reader, and it showed some of the most common fixes for the lean code being replacing/cleaning the MAF sensor or replacing O2 sensors. So I cleaned the MAF sensor with MAF cleaner and that seemed to fix the problem.
After that, the car ran perfectly fine all day from about 7am until 4pm. I do gig work (mainly Instacart & Walmart Spark), so I was driving all throughout the day, but prob under or around 100 ish miles today.
Then around 4pm, while I was driving, I suddenly heard the sound in the video accompanied by roughness and shaking. I immediately pulled into a parking lot, turned the car off, and tried to diagnose what was wrong but couldn't figure it out. I didn't notice anything obviously wrong after inspecting the engine bay. I checked the oil again and it's still at the correct level, the serpentine belt seems fine, the intake hoses seem fine, and I checked the electrical connectors I could see.
After a while I decided to record the video included to show or post about it later.
The really confusing part is that this didn't result in any new check engine codes. There are still only two current codes:
- P1406 (DPFE sensor downstream hose unplugged or clogged). This has been on for a long time and has never really affected anything noticeably, as far as I can tell.
- P1131 (lack of HO2S11 switch, sensor indicates lean). This is the code that first popped up around 6am that morning when the car was only running slightly rough.
That's the part that's really throwing me for a loop. The P1131 came with the slight roughness that morning, then cleaning the MAF seemed to fix that completely and the car ran buttery smooth for roughly 9 hours. Then around 4pm this much more severe roughness/shaking and the sound in the video suddenly started, but there aren't any new codes.
I would think something like a bad spark plug, ignition coil, or fuel injector could be the issue but idk why Im not getting any codes for that. Maybe if I let my car run longer some new useful code would appear but idk if it's risky to do so.
The car is currently parked in a grocery store/shopping center parking lot about 50 mins from where I live, and I'm trying to figure out whether I can diagnose/fix this myself there or if I need to get it towed. I really prefer to do everything myself unless it's almost impossible to do so, I even replaced the intake manifold a couple years back myself btw
TL;DR: Around 6am car had a new P1131 lean code and slight but consistent roughness. Cleaned the MAF and the car ran buttery smooth for the rest of the day until around 4pm, when it suddenly started making the sound in the video along with severe roughness, even at idle. No new codes afterward. Anyone have an idea what this could be or what I should check next?