The red arrow points to a bolt on the back of the engine near the upstream O2 sensor. I noticed that it was sticking out and thought it was weird but when i touched it the washer just flopped around. Can anyone identify this bolt?
What is this bolt?? (1 Viewer)
- Thread starter CarolinaGX
- Start date
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- Thread starter
- #2
The head is 14mm. I tightened it up with a ratcheting wrench. I would love to know what it is and why it was loose.
That’s a weird one, I’ll take a look at mine when I get a chance
- Thread starter
- #4
I would love to know what it is and why it backed out. Perhaps it was the cause of my P0420 code? I replaced the downstream O2 and it didnt help. Then I replaced the upstream O2 and in the process noticed this bolt and tightened it up. After 300 miles, no more light 
It’s the P0420 bypass bolt! Lol
- Thread starter
- #6
