[JavaBrewer]

Hi all,

In preparation for a 3 day drive up the coast I took the 86 Carrera in to a very reputable shop here in San Diego for an oil change and quick once over. I also wanted them to verify that my analysis of 2 leaking oil return tubes was correct. I plan to replace all 4 next month using the handy two piece units sold by our host...my first "oily hands" Porsche project!

Anyway the shop notified me that my O2 sensor connection was bad and that they corrected it. Now instead of a default rich "limp-home" mixture the computer is getting the information it needs to optimize engine settings. The shop said this change would make the idle wander a bit but I should notice increased MPG and performance. Too soon to tell on the MPG but I do notice the engine pulls harder and faster, not a lot, but noticeable. The idle is definitely less stable but what really bothers me is I now have a stumble/hesitation at the 3-4K RPM range (prime freeway cruising) and also at various other points under the 3K range. This all occurs regardless of the loud pedal position but does seem less pronounced with right foot firmly depressed. Funny how speed and engine noise makes that go away!

At this point I'm thinking of disconnecting the O2 sensor (cat bypass in use) to restore overall driveability for this weekend and then later replacing the O2 sensor. Do the symptoms I descibe sound like a dying/dead O2 sensor? Since I've been driving with non-functional O2 sensor for several months I figure another couple of days isn't going to hurt anything. Bad idea?

Thanks for your time!