Sudden rough running & simple fix
06-14-2016 | 09:16 PM
#1
Thread Starter
Burning Brakes
Joined: Jul 2010
Posts: 1,103
Likes: 56
Sudden rough running & simple fix
Jumped in the S2 today and upon starting it ran rough and stinky rich. On the road it was no better, so turned around and went home. Pulled both the fuel damper and fuel pressure regulator vacuum hoses and no gas 
Figured it was the O2 sensor so let it cool down and got under it to check the size to see if I had a flare nut wrench that big. I touched it and it was loose, a couple of turns worth. Tightened it down and it fired right up and ran smoothly. An annoying exhaust rattle when cold I could never track down disappeared too
Figured it was the O2 sensor so let it cool down and got under it to check the size to see if I had a flare nut wrench that big. I touched it and it was loose, a couple of turns worth. Tightened it down and it fired right up and ran smoothly. An annoying exhaust rattle when cold I could never track down disappeared too
Last edited by jhowell371; 06-14-2016 at 09:22 PM. Reason: grammar
06-21-2016 | 12:13 PM
#6
Thread Starter
Burning Brakes
Joined: Jul 2010
Posts: 1,103
Likes: 56
I figured I would play hell getting it out for replacement and was really surprised when it was loose. An exhaust heat shield rattle of an undetermined source was noted on a PPI that was done 18,000 miles ago for a PO I have beat on the exhaust system numerous times with a rubber mallet trying to track it down, touching all the various components and shields but never touched the #%^**% O2 sensor.
06-21-2016 | 12:33 PM
#7
Rennlist Member
Joined: May 2004
Posts: 2,822
Likes: 171
From: Poconos PA
Just had mine removed. It was the original from 1983. Needless to say, it wasn't cooperative coming out. Lots of heat and threads lost in the bung. Had to run a tap through. Now it's good for another 33 years!
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06-23-2016 | 03:24 PM
#9
Pro
Joined: May 2010
Posts: 729
Likes: 1
I had this happen with my '83. Replaced the O2 sensor. A while later developed an annoying rattle. Thought it was the heat shield by the starter/bellhousing. Replaced it with a better unit. Still rattled. Assumed it was exhaust. Finally took it to a shop and they the O2 sensor loose. Tightened it up and ggod to go.
Not long after, the rattle came back. So I crawled under and it was the sensor again. Tightened it up again.
Then it happened again. So I pulled the sensor and put a bit of blue threadlocker on it. What do you know. It's been fine. No more coming loose.
Not long after, the rattle came back. So I crawled under and it was the sensor again. Tightened it up again.
Then it happened again. So I pulled the sensor and put a bit of blue threadlocker on it. What do you know. It's been fine. No more coming loose.