Been having a nightmare of a month with my 2005 Ford Focus ZX4.
About a month ago, my car suddenly began bogging down when I was driving on the highway. From the driver side, I hear the engine getting louder or like something is clogged whenever it starts happening. My speed also decreases until the car just jerks and bucks like it’s being starved of something. I had my fuel pump, fuel filter, airbox, and MAF changed. I don’t get any codes or even a CEL.
Any clue what the issue could be? I was thinking it possibly could be a clogged catalytic converter
Video of the problem:
An exhaust shop can check to see if you have a clogged Cat (exhaust)…
Or you can remove the upstream O2 sensor and see if it stops the bog, or if able (depending on manufacture) unbolt the Cat and see if it still bogs…
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I’m gonna give that a try today. I’m really hoping it’s not the cat as that’s a pretty tough job to do
Suggest to measure your intake-manifold vacuum reading at warm idle.
Me thinks sarxlives has left the building.
Whoops, sorry. I forgot I posted here. The problem has repaired itself oddly enough. I had my fuel pump changed and did a intake vaccum test and everything came back normal. Since like a month ago, I haven’t gotten any issues
Hopefully this problem is fixed. If problem resumes, there could still be a cat problem. That part is basically just a hollow metal tube filled with ceramic material. The ceramic material is configured with small holes so exhaust gasses will readily go right through it, from front to back. Sideways, not so much.
Sometimes the ceramic, or a section, will break away from the metal tube. When that happens, depending on where it ends up, the exhaust gasses may not be able to get through b/c it winds up oriented sideways. So when aligned ok, cat works fine, go over a bump, sideways, cat won’t pass exhaust gasses and engine bogs. If you’re able to test engine in that condition, it would show considerable less than normal idle intake manifold vacuum.
Interesting fact: Cats were at best a lab curiosity, no idea if they’d be robust enough to work in vehicle exhaust systems, as late as the early 1970’s
