Thanks, Lee,
I also suspect that my o2 sensor could be failing.
First I want to use a half tank of gas to see whether the new plugs and airfilter change brings any improvements in fuel consumption, then I will try replacing the o2 sensor.

Wouldn't a failing crankshaft-position sensor cause hectic/rough idle too?

when i lost a cps.... the car would start perfectly when cold.. then after driving it a bit...it was just stall.... dead stall. at first i could restart it.. but in a matter of a couple of weeks... it would dead stall... and i had to wait for the car to cool down a bit... once it took 30 minutes to cool down.. i replaced the cps and never had a problem.... no idle issues when running... there is also a camshaft position sensor which doesn't ever seem to go bad... crankshaft sensor will take you 45 minutes to replace the first time....

this was on our 89 ce... with a 103 engine....

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1989 300ce 129k
( facelifted front,updated tail lights, lowered suspension,bilstein sports, lorinser front spoiler, MOMO steering wheel, remus exhaust,stainless steel brake lines). (Gone)

1997 s320 154k (what a ride). Sold with 179k miles. Replaced with Hyundai Equus

1994 e320 Cabriolet 108k



1972 280se 4.5 153k Owned for 12 yrs, sorry I sold it


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