I’m new to this forum and a Mercedes owner but am doing some research for a friend who is beginning to feel that his mechanic is taking advantage of him. He's got a '90 Civic 4-door and just paid $400 to have the distributor cap and rotor replaced. My friend said he watched the guy take all of 10 minutes to replace these parts and realized he could have done this himself. Now he’s getting a rough idle after the distributor replacement and the mechanic now says his O2 sensor needs replacement for a mere $200 more! I told him to hold off on any more trips to this guy and told him I will replace the 02 sensor next time my friend comes to visit me. In my optimism I am thinking maybe the Japanese were more technically savvy than the Germans and located the O2 sensor so that it is accessible from under the hood so I won’t have to put the car up on stands. Maybe it’s so easily accessible that I can talk my friend thru the O2 sensor change over the phone! Can someone tell me where the O2 sensor is located on this Civic? Also, any recommendations on Walker, Denso or Bosch sensor? Thanks for your help.

 

If that 90 is anything like my 91 DX, the O2 sensor is bolted to the left of the exhaust manifold, VERY visible and VERY accessible from the top.

 

did he do a scan to know that?
is the check engine light on?

pretty sure it is like my 88 - need to remove the passenger side radiator fan.
i think that you can get to it with a wrench then - may even be able to use a cresent.

think i bought a bosch (general purpose) for 18 to $19.