Plastic fell in upstream O2 sensor port

Joined
Mar 17, 2026
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14
Had code P0420 so I checked it out with a bore scope and saw minor blockage on the catalytic converter.

Took out the upstream O2 sensor and sprayed some throttle body cleaner in there, and half way through the can, the straw fell down there.

Car is still cold. I can see the straw with the bore scope but it's way down there and I can't grab it.

So I guess my options are?
let it melt when I drive and hope for the best
Remove the catalytic converter and get it out
 
Let it melt out. No harm done. If any harm was done it was spraying chemicals into the converter.
 
The cat is going to need replacement at some point soon, the burning of the plastic straw is not going to make any difference to its longevity.
 
... and if that grabber doesn't grab it, wrap it with tape-- first layer normal, then reverse it so the 2nd layer is sticky-side-out.
 
I appreciate all the comments and suggestions.

I could only get within a couple of inches with the borescope. Couldn't touch it after an hour of trying. Either it's buried in a wedge or I just couldn't move it around the right way. I drove home 40 miles at 3000-4000rpm and the check engine light turned off and the car felt fine.

I'll update with pics in a week or so when I have a chance to look in there again. I wonder if there's visible melted plastic somewhere or if it just vanished.
 
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