[V8] 7 hour oxygen sensor

QuickAudi at aol.com QuickAudi at aol.com
Mon Apr 12 18:15:37 EDT 2004

Yes, the subject line is correct.  My oxygen sensor removal and replacement took 7 hours.  After the VAG-COM gave an intermittent OXS code (came on, then off, then on, etc.), I decided to remove it at the house.  So, Sunday afternoon, I lifted the 4000 lb. pig up high enough with a floor jack for me to squeeze under.  Of course, the oxygen sensor ratchet tool wouldn't fit, so I cut the wires (no going back now!) and put the 7/8" wrench on the back end.  It didn't budge, despite all of my bodybuilding as of late.  Next up, get the baby mallet and whack away.  It budged.  So, the wrench and I get to work, and after about 100 rotations (no exaggeration) of me turning then hammering, I start to wonder if it wasn't screwed through the front of the engine.  Extremely close inspection reveals that it is about halfway out, and when it starts to hop onto the next thread and come out, it goes back in.  I knew that wasn't good, so with some persuasion (used the mallet on the sensor to "lift" it, similar to the lift and cut system, but not really) I finally got it out.  I pulled several threads from the sensor out of the hole and surveyed the damage.  Oh yeah, there's no way another sensor is going to go straight back in.  This had me a little over an hour into the project, and I needed a tap.  Well, guess what?  In Waverly, TN, at about 6 p.m. on Easter Sunday, no one has a tap set around.  Go figure.  
Monday morning, dad had done some research and found out that a 18 mm x 1.5 tap should fit (of note, this is also the same size as a spark plug hole.)  No one has a tap over 1/2", so we find a spark plug thread chaser.  It'll have to do.  Using the "work it in a little way, then work it out" method (sometimes required the use of the mallet, other times the big red, solid metal axe), I made some progress in recutting the hole.  When I got it finished, the thread chaser had quite rounded threads, but the job was done.  Dad did the crimping for the new sensor (a Bosch 13913 generic sensor for $40 at Advance) and put the sensor in, and with me working it from below and him from above, we reconnected the sensor to it's hole.  Car started; I'm absolutely enthralled, cause now I can get back to school.  I had to skip class, but I had to be at work that afternoon.
Oh yeah, did it help?  Yeah, probably.  I used to have that "stepping acceleration" that everyone complained about, and it is much less noticeable/gone, and my acceleration seems to be a little better now.  I'll check gas mileage and let everyone know and also keep updated on the codes and acceleration problems.

'90 V8q (Carmen is happy now)
'86 5kcstq (team doorhandle has struck again!)

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