Some time ago the Quest stalled, stranding my parents. They called me and I told them to turn off the ignition, wait a minute and start it again.
It did start and they made it home, even though the engine ran poorly.
At that time I waiting for the OBDII readers and once they arrived, read the codes. There was a pending code for the throttle pedal position sensor. Fortunately, I first posted on the Quest forum and was told to replace the camshaft position sensor instead. I ordered both and was lucky to replace the front bank CPS first, as that fixed the code and the engine ran fine since.
Then I got the dreadful P1273 code for air/fuel mixture and read about it. Some said that a learning procedure should be followed. I followed it twice and first time waited more than 10 seconds to shut off the engine, so the code came back in the next about 10-15 miles. I repeated the procedure and timed exactly 10 seconds. Then I drove about 70 miles to work and back and the code came back only after about 50 miles.
I repeated the procedure and drove to work the day after. On my way to work the light did not come on, but I heard a pop and the exhaust broke. It turned out that the O2 sensor bung popped out. My mechanic welded it back in, but ever since I picked up the van it backfires 3-4 times when I start and shut off the engine. What could possibly cause that? Does it mean that the O2 sensor was damaged when it popped? And also, has it popped because there was already incorrect air/fuel mixture and once it backfired it popped the bung?
It happened on a highway at very moderate speed, perhaps when I was very mildly accelerating from 30 to 40 miles an hour.
I am assuming that once popped, the O2 sensor just hung there, could it possibly break from dangling?